cfg - almost nowhere

3 files changed, 1959 insertions, 0 deletions

diff --git a/src/luarocks/core/cfg (conflicted).tl b/src/luarocks/core/cfg (conflicted).tl
new file mode 100644
index 00000000..f4c78ebf
--- /dev/null
+++ b/src/luarocks/core/cfg (conflicted).tl
@@ -0,0 +1,978 @@
+
+--- Configuration for LuaRocks.
+-- Tries to load the user's configuration file and
+-- defines defaults for unset values. See the
+-- <a href="http://luarocks.org/en/Config_file_format">config
+-- file format documentation</a> for details.
+--
+-- End-users shouldn't edit this file. They can override any defaults
+-- set in this file using their system-wide or user-specific configuration
+-- files. Run `luarocks` with no arguments to see the locations of
+-- these files in your platform.
+
+local table, pairs, require, os, pcall, ipairs, package, type, assert = --!
+      table, pairs, require, os, pcall, ipairs, package, type, assert
+
+local dir = require("luarocks.core.dir") --!
+local util = require("luarocks.core.util")
+local persist = require("luarocks.core.persist")
+local sysdetect = require("luarocks.core.sysdetect")
+local vers = require("luarocks.core.vers")
+
+local record cfg
+
+end
+
+--------------------------------------------------------------------------------
+
+local program_version = "dev" --!
+
+local is_windows = package.config:sub(1,1) == "\\" --!
+
+-- Set order for platform overrides.
+-- More general platform identifiers should be listed first,
+-- more specific ones later.
+local platform_order = {
+   -- Unixes
+   "unix",
+   "bsd",
+   "solaris",
+   "netbsd",
+   "openbsd",
+   "freebsd",
+   "dragonfly",
+   "linux",
+   "macosx",
+   "cygwin",
+   "msys",
+   "haiku",
+   -- Windows
+   "windows",
+   "win32",
+   "mingw",
+   "mingw32",
+   "msys2_mingw_w64",
+}
+
+local type Config = record --!
+   home: any
+   lua_version: any
+   target_cpu: any
+   variables: {any: any}
+   os_getenv: any
+   rocks_trees: any
+   rocks_servers: any
+   dump_env: function()
+end
+
+local function detect_sysconfdir()
+   if not debug then
+      return
+   end
+   local src = debug.getinfo(1, "S").source
+   if not src then
+      return
+   end
+   src = dir.normalize(src)
+   if src:sub(1, 1) == "@" then
+      src = src:sub(2)
+   end
+   local basedir = src:match("^(.*)[\\/]luarocks[\\/]core[\\/]cfg.lua$")
+   if not basedir then
+      return
+   end
+   -- If installed in a Unix-like tree, use a Unix-like sysconfdir
+   local installdir = basedir:match("^(.*)[\\/]share[\\/]lua[\\/][^/]*$")
+   if installdir then
+      if installdir == "/usr" then
+         return "/etc/luarocks" --!
+      end
+      return dir.path(installdir, "etc", "luarocks")
+   end
+   -- Otherwise, use base directory of sources
+   return basedir
+end
+
+-- local load_config_file --!
+do
+   -- Create global environment for the config files;
+   local function env_for_config_file(cfg: Config, platforms: {any: any}): {any: any} --!
+      local platforms_copy = {}
+      for k,v in pairs(platforms) do
+         platforms_copy[k] = v
+      end
+
+      local e: {any: any} --!
+      e = {
+         home = cfg.home,
+         lua_version = cfg.lua_version,
+         platforms = platforms_copy,
+         processor = cfg.target_cpu,   -- remains for compat reasons
+         target_cpu = cfg.target_cpu,  -- replaces `processor`
+         os_getenv = os.getenv,
+         variables = cfg.variables or {},
+         dump_env = function()
+            -- debug function, calling it from a config file will show all
+            -- available globals to that config file
+            print(util.show_table(e, "global environment"))
+         end,
+      }
+      return e
+   end
+
+   -- Merge values from config files read into the `cfg` table
+   local function merge_overrides(cfg: Config, overrides: Config)
+      -- remove some stuff we do not want to integrate
+      overrides.os_getenv = nil
+      overrides.dump_env = nil
+      -- remove tables to be copied verbatim instead of deeply merged
+      if overrides.rocks_trees   then cfg.rocks_trees   = nil end
+      if overrides.rocks_servers then cfg.rocks_servers = nil end
+      -- perform actual merge
+      util.deep_merge(cfg, overrides)
+   end
+
+   local function update_platforms(platforms: {any: any}, overrides: {any: any})
+      if overrides[1] then
+         for k, _ in pairs(platforms) do
+            platforms[k] = nil
+         end
+         for _, v in ipairs(overrides) do
+            platforms[v] = true
+         end
+         -- set some fallback default in case the user provides an incomplete configuration.
+         -- LuaRocks expects a set of defaults to be available.
+         if not (platforms.unix or platforms.windows) then
+            platforms[is_windows and "windows" or "unix"] = true
+         end
+      end
+   end
+
+   -- Load config file and merge its contents into the `cfg` module table.
+   -- @return filepath of successfully loaded file or nil if it failed
+   local load_config_file = function(cfg: Config, platforms: {any: any}, filepath: string): string --!
+      local result, err, errcode = persist.load_into_table(filepath, env_for_config_file(cfg, platforms))
+      if (not result) and errcode ~= "open" then
+         -- errcode is either "load" or "run"; bad config file, so error out
+         return nil, err, "config"
+      end
+      if result then
+         -- success in loading and running, merge contents and exit
+         update_platforms(platforms, result.platforms)
+         result.platforms = nil
+         merge_overrides(cfg, result)
+         return filepath
+      end
+      return nil -- nothing was loaded
+   end
+end
+
+local platform_sets = {
+   freebsd = { unix = true, bsd = true, freebsd = true },
+   openbsd = { unix = true, bsd = true, openbsd = true },
+   dragonfly = { unix = true, bsd = true, dragonfly = true },
+   solaris = { unix = true, solaris = true },
+   windows = { windows = true, win32 = true },
+   cygwin = { unix = true, cygwin = true },
+   macosx = { unix = true, bsd = true, macosx = true, macos = true },
+   netbsd = { unix = true, bsd = true, netbsd = true },
+   haiku = { unix = true, haiku = true },
+   linux = { unix = true, linux = true },
+   mingw = { windows = true, win32 = true, mingw32 = true, mingw = true },
+   msys = { unix = true, cygwin = true, msys = true },
+   msys2_mingw_w64 = { windows = true, win32 = true, mingw32 = true, mingw = true, msys = true, msys2_mingw_w64 = true },
+}
+
+local function make_platforms(system: string): {any: boolean} --! :System
+   -- fallback to Unix in unknown systems
+   return platform_sets[system] or { unix = true }
+end
+
+--------------------------------------------------------------------------------
+
+local function make_defaults(lua_version: string, target_cpu: string, platforms: {any: any}, home: string): {any: any} --!
+
+   -- Configure defaults:
+   local defaults = {
+
+      local_by_default = false,
+      accept_unknown_fields = false,
+      fs_use_modules = true,
+      hooks_enabled = true,
+      deps_mode = "one",
+      no_manifest = false,
+      check_certificates = false,
+
+      cache_timeout = 60,
+      cache_fail_timeout = 86400,
+
+      lua_modules_path = dir.path("share", "lua", lua_version),
+      lib_modules_path = dir.path("lib", "lua", lua_version),
+      rocks_subdir = dir.path("lib", "luarocks", "rocks-"..lua_version),
+
+      arch = "unknown",
+      lib_extension = "unknown",
+      external_lib_extension = "unknown", --?
+      static_lib_extension = "unknown", --?
+      obj_extension = "unknown",
+      link_lua_explicitly = false,
+
+      external_deps_dirs = {}, --?
+      external_deps_patterns = {}, --?
+      runtime_external_deps_patterns = {}, --?
+
+      export_path_separator = "", --?
+      wrapper_suffix = "", --?
+
+
+      rocks_servers = {
+         {
+           "https://luarocks.org",
+           "https://raw.githubusercontent.com/rocks-moonscript-org/moonrocks-mirror/master/",
+           "https://loadk.com/luarocks/",
+         }
+      },
+      disabled_servers = {},
+
+      upload = {
+         server = "https://luarocks.org",
+         tool_version = "1.0.0",
+         api_version = "1",
+      },
+
+      lua_extension = "lua",
+      connection_timeout = 30,  -- 0 = no timeout
+
+      makefile = "", --?
+      local_cache = "" , --?
+      web_browser = "", --?
+      cmake_generator = "", --?
+      gcc_rpath = false, --?
+
+      variables = {
+         MAKE = os.getenv("MAKE") or "make",
+         CC = os.getenv("CC") or "cc",
+         LD = os.getenv("CC") or "ld",
+         AR = os.getenv("AR") or "ar",
+         RANLIB = os.getenv("RANLIB") or "ranlib",
+
+         CVS = "cvs",
+         GIT = "git",
+         SSCM = "sscm",
+         SVN = "svn",
+         HG = "hg",
+
+         GPG = "gpg",
+
+         RSYNC = "rsync",
+         WGET = "wget",
+         SCP = "scp",
+         CURL = "curl",
+
+         PWD = "pwd",
+         MKDIR = "mkdir",
+         RMDIR = "rmdir",
+         CP = "cp",
+         LN = "ln",
+         LS = "ls",
+         RM = "rm",
+         FIND = "find",
+         CHMOD = "chmod",
+         ICACLS = "icacls",
+         MKTEMP = "mktemp",
+
+         ZIP = "zip",
+         UNZIP = "unzip -n",
+         GUNZIP = "gunzip",
+         BUNZIP2 = "bunzip2",
+         TAR = "tar",
+
+         MD5SUM = "md5sum",
+         OPENSSL = "openssl",
+         MD5 = "md5",
+         TOUCH = "touch",
+
+         CMAKE = "cmake",
+         SEVENZ = "7z",
+
+         RSYNCFLAGS = "--exclude=.git -Oavz",
+         CURLNOCERTFLAG = "",
+         WGETNOCERTFLAG = "",
+
+         RC = "", --?
+         MT = "", --?
+         CFLAGS = "", --?
+         LDFLAGS = "", --?
+         LIBFLAG = "", --?
+         TEST = "", --?
+      },
+
+      external_deps_subdirs = {
+         bin = "bin",
+         lib = "lib",
+         include = "include"
+      },
+      runtime_external_deps_subdirs = {
+         bin = "bin",
+         lib = "lib",
+         include = "include"
+      },
+   }
+
+   if platforms.windows then
+
+      defaults.arch = "win32-"..target_cpu
+      defaults.lib_extension = "dll"
+      defaults.external_lib_extension = "dll"
+      defaults.static_lib_extension = "lib"
+      defaults.obj_extension = "obj"
+      defaults.external_deps_dirs = {
+         dir.path("c:", "external"),
+         dir.path("c:", "windows", "system32"),
+      }
+
+      defaults.makefile = "Makefile.win"
+      defaults.variables.PWD = "echo %cd%"
+      defaults.variables.MKDIR = "md"
+      defaults.variables.MAKE = os.getenv("MAKE") or "nmake"
+      defaults.variables.CC = os.getenv("CC") or "cl"
+      defaults.variables.RC = os.getenv("WINDRES") or "rc"
+      defaults.variables.LD = os.getenv("LINK") or "link"
+      defaults.variables.MT = os.getenv("MT") or "mt"
+      defaults.variables.AR = os.getenv("AR") or "lib"
+      defaults.variables.CFLAGS = os.getenv("CFLAGS") or "/nologo /MD /O2"
+      defaults.variables.LDFLAGS = os.getenv("LDFLAGS")
+      defaults.variables.LIBFLAG = "/nologo /dll"
+
+      defaults.external_deps_patterns = {
+         bin = { "?.exe", "?.bat" },
+         lib = { "?.lib", "lib?.lib", "?.dll", "lib?.dll" },
+         include = { "?.h" }
+      }
+      defaults.runtime_external_deps_patterns = {
+         bin = { "?.exe", "?.bat" },
+         lib = { "?.dll", "lib?.dll" },
+         include = { "?.h" }
+      }
+      defaults.export_path_separator = ";"
+      defaults.wrapper_suffix = ".bat"
+
+      local localappdata = os.getenv("LOCALAPPDATA")
+      if not localappdata then
+         -- for Windows versions below Vista
+         localappdata = dir.path((os.getenv("USERPROFILE") or dir.path("c:", "Users", "All Users")), "Local Settings", "Application Data")
+      end
+      defaults.local_cache = dir.path(localappdata, "LuaRocks", "Cache")
+      defaults.web_browser = "start"
+
+      defaults.external_deps_subdirs.lib = { "lib", "", "bin" }
+      defaults.runtime_external_deps_subdirs.lib = { "lib", "", "bin" }
+      defaults.link_lua_explicitly = true
+      defaults.fs_use_modules = false
+   end
+
+   if platforms.mingw32 then
+      defaults.obj_extension = "o"
+      defaults.static_lib_extension = "a"
+      defaults.external_deps_dirs = {
+         dir.path("c:", "external"),
+         dir.path("c:", "mingw"),
+         dir.path("c:", "windows", "system32"),
+      }
+      defaults.cmake_generator = "MinGW Makefiles"
+      defaults.variables.MAKE = os.getenv("MAKE") or "mingw32-make"
+      if target_cpu == "x86_64" then
+         defaults.variables.CC = os.getenv("CC") or "x86_64-w64-mingw32-gcc"
+         defaults.variables.LD = os.getenv("CC") or "x86_64-w64-mingw32-gcc"
+      else
+         defaults.variables.CC = os.getenv("CC") or "mingw32-gcc"
+         defaults.variables.LD = os.getenv("CC") or "mingw32-gcc"
+      end
+      defaults.variables.AR = os.getenv("AR") or "ar"
+      defaults.variables.RC = os.getenv("WINDRES") or "windres"
+      defaults.variables.RANLIB = os.getenv("RANLIB") or "ranlib"
+      defaults.variables.CFLAGS = os.getenv("CFLAGS") or "-O2"
+      defaults.variables.LDFLAGS = os.getenv("LDFLAGS")
+      defaults.variables.LIBFLAG = "-shared"
+      defaults.makefile = "Makefile"
+      defaults.external_deps_patterns = {
+         bin = { "?.exe", "?.bat" },
+         -- mingw lookup list from http://stackoverflow.com/a/15853231/1793220
+         -- ...should we keep ?.lib at the end? It's not in the above list.
+         lib = { "lib?.dll.a", "?.dll.a", "lib?.a", "cyg?.dll", "lib?.dll", "?.dll", "?.lib" },
+         include = { "?.h" }
+      }
+      defaults.runtime_external_deps_patterns = {
+         bin = { "?.exe", "?.bat" },
+         lib = { "cyg?.dll", "?.dll", "lib?.dll" },
+         include = { "?.h" }
+      }
+      defaults.link_lua_explicitly = true
+   end
+
+   if platforms.unix then
+      defaults.lib_extension = "so"
+      defaults.static_lib_extension = "a"
+      defaults.external_lib_extension = "so"
+      defaults.obj_extension = "o"
+      defaults.external_deps_dirs = { "/usr/local", "/usr", "/" }
+
+      defaults.variables.CFLAGS = os.getenv("CFLAGS") or "-O2"
+      -- we pass -fPIC via CFLAGS because of old Makefile-based Lua projects
+      -- which didn't have -fPIC in their Makefiles but which honor CFLAGS
+      if not defaults.variables.CFLAGS:match("-fPIC") then
+         defaults.variables.CFLAGS = defaults.variables.CFLAGS.." -fPIC"
+      end
+
+      defaults.variables.LDFLAGS = os.getenv("LDFLAGS")
+
+      defaults.cmake_generator = "Unix Makefiles"
+      defaults.variables.CC = os.getenv("CC") or "gcc"
+      defaults.variables.LD = os.getenv("CC") or "gcc"
+      defaults.gcc_rpath = true
+      defaults.variables.LIBFLAG = "-shared"
+      defaults.variables.TEST = "test"
+
+      defaults.external_deps_patterns = {
+         bin = { "?" },
+         lib = { "lib?.a", "lib?.so", "lib?.so.*" },
+         include = { "?.h" }
+      }
+      defaults.runtime_external_deps_patterns = {
+         bin = { "?" },
+         lib = { "lib?.so", "lib?.so.*" },
+         include = { "?.h" }
+      }
+      defaults.export_path_separator = ":"
+      defaults.wrapper_suffix = ""
+      local xdg_cache_home = os.getenv("XDG_CACHE_HOME") or home.."/.cache"
+      defaults.local_cache = xdg_cache_home.."/luarocks"
+      defaults.web_browser = "xdg-open"
+   end
+
+   if platforms.cygwin then
+      defaults.lib_extension = "so" -- can be overridden in the config file for mingw builds
+      defaults.arch = "cygwin-"..target_cpu
+      defaults.cmake_generator = "Unix Makefiles"
+      defaults.variables.CC = "echo -llua | xargs " .. (os.getenv("CC") or "gcc")
+      defaults.variables.LD = "echo -llua | xargs " .. (os.getenv("CC") or "gcc")
+      defaults.variables.LIBFLAG = "-shared"
+      defaults.link_lua_explicitly = true
+   end
+
+   if platforms.msys then
+      -- msys is basically cygwin made out of mingw, meaning the subsytem is unixish
+      -- enough, yet we can freely mix with native win32
+      defaults.external_deps_patterns = {
+         bin = { "?.exe", "?.bat", "?" },
+         lib = { "lib?.so", "lib?.so.*", "lib?.dll.a", "?.dll.a",
+                 "lib?.a", "lib?.dll", "?.dll", "?.lib" },
+         include = { "?.h" }
+      }
+      defaults.runtime_external_deps_patterns = {
+         bin = { "?.exe", "?.bat" },
+         lib = { "lib?.so", "?.dll", "lib?.dll" },
+         include = { "?.h" }
+      }
+      if platforms.mingw then
+         -- MSYS2 can build Windows programs that depend on
+         -- msys-2.0.dll (based on Cygwin) but MSYS2 is also designed
+         -- for building native Windows programs by MinGW. These
+         -- programs don't depend on msys-2.0.dll.
+         local pipe = io.popen("cygpath --windows %MINGW_PREFIX%")
+         local mingw_prefix = pipe:read("*l")
+         pipe:close()
+         defaults.external_deps_dirs = {
+            mingw_prefix,
+            dir.path("c:", "windows", "system32"),
+         }
+         defaults.makefile = "Makefile"
+         defaults.cmake_generator = "MSYS Makefiles"
+         defaults.local_cache = dir.path(home, ".cache", "luarocks")
+         defaults.variables.MAKE = os.getenv("MAKE") or "make"
+         defaults.variables.CC = os.getenv("CC") or "gcc"
+         defaults.variables.RC = os.getenv("WINDRES") or "windres"
+         defaults.variables.LD = os.getenv("CC") or "gcc"
+         defaults.variables.MT = os.getenv("MT") or nil
+         defaults.variables.AR = os.getenv("AR") or "ar"
+         defaults.variables.RANLIB = os.getenv("RANLIB") or "ranlib"
+
+         defaults.variables.CFLAGS = os.getenv("CFLAGS") or "-O2 -fPIC"
+         if not defaults.variables.CFLAGS:match("-fPIC") then
+            defaults.variables.CFLAGS = defaults.variables.CFLAGS.." -fPIC"
+         end
+
+         defaults.variables.LIBFLAG = "-shared"
+      end
+   end
+
+   if platforms.bsd then
+      defaults.variables.MAKE = "gmake"
+      defaults.gcc_rpath = false
+      defaults.variables.CC = os.getenv("CC") or "cc"
+      defaults.variables.LD = os.getenv("CC") or defaults.variables.CC
+   end
+
+   if platforms.macosx then
+      defaults.variables.MAKE = os.getenv("MAKE") or "make"
+      defaults.external_lib_extension = "dylib"
+      defaults.arch = "macosx-"..target_cpu
+      defaults.variables.LIBFLAG = "-bundle -undefined dynamic_lookup -all_load"
+      local version = util.popen_read("sw_vers -productVersion")
+      if not (version:match("^%d+%.%d+%.%d+$") or version:match("^%d+%.%d+$")) then
+         version = "10.3"
+      end
+      version = vers.parse_version(version)
+      if version >= vers.parse_version("11.0") then
+         version = vers.parse_version("11.0")
+      elseif version >= vers.parse_version("10.10") then
+         version = vers.parse_version("10.8")
+      elseif version >= vers.parse_version("10.5") then
+         version = vers.parse_version("10.5")
+      else
+         defaults.gcc_rpath = false
+      end
+      defaults.variables.CC = "env MACOSX_DEPLOYMENT_TARGET="..tostring(version).." gcc"
+      defaults.variables.LD = "env MACOSX_DEPLOYMENT_TARGET="..tostring(version).." gcc"
+      defaults.web_browser = "open"
+
+      -- XCode SDK
+      local sdk_path = util.popen_read("xcrun --show-sdk-path 2>/dev/null")
+      if sdk_path then
+         table.insert(defaults.external_deps_dirs, sdk_path .. "/usr")
+         table.insert(defaults.external_deps_patterns.lib, 1, "lib?.tbd")
+         table.insert(defaults.runtime_external_deps_patterns.lib, 1, "lib?.tbd")
+      end
+
+      -- Homebrew
+      table.insert(defaults.external_deps_dirs, "/usr/local/opt")
+      defaults.external_deps_subdirs.lib = { "lib", "" }
+      defaults.runtime_external_deps_subdirs.lib = { "lib", "" }
+      table.insert(defaults.external_deps_patterns.lib, 1, "/?/lib/lib?.dylib")
+      table.insert(defaults.runtime_external_deps_patterns.lib, 1, "/?/lib/lib?.dylib")
+   end
+
+   if platforms.linux then
+      defaults.arch = "linux-"..target_cpu
+
+      local gcc_arch = util.popen_read("gcc -print-multiarch 2>/dev/null")
+      if gcc_arch and gcc_arch ~= "" then
+         defaults.external_deps_subdirs.lib = { "lib/" .. gcc_arch, "lib64", "lib" }
+         defaults.runtime_external_deps_subdirs.lib = { "lib/" .. gcc_arch, "lib64", "lib" }
+      else
+         defaults.external_deps_subdirs.lib = { "lib64", "lib" }
+         defaults.runtime_external_deps_subdirs.lib = { "lib64", "lib" }
+      end
+   end
+
+   if platforms.freebsd then
+      defaults.arch = "freebsd-"..target_cpu
+   elseif platforms.dragonfly then
+      defaults.arch = "dragonfly-"..target_cpu
+   elseif platforms.openbsd then
+      defaults.arch = "openbsd-"..target_cpu
+   elseif platforms.netbsd then
+      defaults.arch = "netbsd-"..target_cpu
+   elseif platforms.solaris then
+      defaults.arch = "solaris-"..target_cpu
+      defaults.variables.MAKE = "gmake"
+   end
+
+   -- Expose some more values detected by LuaRocks for use by rockspec authors.
+   defaults.variables.LIB_EXTENSION = defaults.lib_extension
+   defaults.variables.OBJ_EXTENSION = defaults.obj_extension
+
+   return defaults
+end
+
+local function use_defaults(cfg, defaults)
+
+   -- Populate variables with values from their 'defaults' counterparts
+   -- if they were not already set by user.
+   if not cfg.variables then
+      cfg.variables = {}
+   end
+   for k,v in pairs(defaults.variables) do
+      if not cfg.variables[k] then
+         cfg.variables[k] = v
+      end
+   end
+
+   util.deep_merge_under(cfg, defaults)
+
+   -- FIXME get rid of this
+   if not cfg.check_certificates then
+      cfg.variables.CURLNOCERTFLAG = "-k"
+      cfg.variables.WGETNOCERTFLAG = "--no-check-certificate"
+   end
+end
+
+--------------------------------------------------------------------------------
+
+local cfg = {}
+
+--- Initializes the LuaRocks configuration for variables, paths
+-- and OS detection.
+-- @param detected table containing information detected about the
+-- environment. All fields below are optional:
+-- * lua_version (in x.y format, e.g. "5.3")
+-- * lua_bindir (e.g. "/usr/local/bin")
+-- * lua_dir (e.g. "/usr/local")
+-- * lua (e.g. "/usr/local/bin/lua-5.3")
+-- * project_dir (a string with the path of the project directory
+--   when using per-project environments, as created with `luarocks init`)
+-- @param warning a logging function for warnings that takes a string
+-- @return true on success; nil and an error message on failure.
+function cfg.init(detected, warning)
+   detected = detected or {}
+
+   local exit_ok = true
+   local exit_err = nil
+   local exit_what = nil
+
+   local hc_ok, hardcoded = pcall(require, "luarocks.core.hardcoded")
+   if not hc_ok then
+      hardcoded = {}
+   end
+
+   local init = cfg.init
+
+   ----------------------------------------
+   -- Reset the cfg table.
+   ----------------------------------------
+
+   for k, _ in pairs(cfg) do
+      cfg[k] = nil
+   end
+
+   cfg.program_version = program_version
+
+   if hardcoded.IS_BINARY then
+      cfg.is_binary = true
+   end
+
+   -- Use detected values as defaults, overridable via config files or CLI args
+
+   local hardcoded_lua = hardcoded.LUA
+   local hardcoded_lua_dir = hardcoded.LUA_DIR
+   local hardcoded_lua_bindir = hardcoded.LUA_BINDIR
+   local hardcoded_lua_incdir = hardcoded.LUA_INCDIR
+   local hardcoded_lua_libdir = hardcoded.LUA_LIBDIR
+   local hardcoded_lua_version = hardcoded.LUA_VERSION or _VERSION:sub(5)
+
+   -- if --lua-version or --lua-dir are passed from the CLI,
+   -- don't use the hardcoded paths at all
+   if detected.given_lua_version or detected.given_lua_dir then
+      hardcoded_lua = nil
+      hardcoded_lua_dir = nil
+      hardcoded_lua_bindir = nil
+      hardcoded_lua_incdir = nil
+      hardcoded_lua_libdir = nil
+      hardcoded_lua_version = nil
+   end
+
+   cfg.lua_version = detected.lua_version or hardcoded_lua_version
+   cfg.project_dir = (not hardcoded.FORCE_CONFIG) and detected.project_dir
+
+   do
+      local lua = detected.lua or hardcoded_lua
+      local lua_dir = detected.lua_dir or hardcoded_lua_dir
+      local lua_bindir = detected.lua_bindir or hardcoded_lua_bindir
+      cfg.variables = {
+         LUA = lua,
+         LUA_DIR = lua_dir,
+         LUA_BINDIR = lua_bindir,
+         LUA_LIBDIR = hardcoded_lua_libdir,
+         LUA_INCDIR = hardcoded_lua_incdir,
+      }
+   end
+
+   cfg.init = init
+
+   ----------------------------------------
+   -- System detection.
+   ----------------------------------------
+
+   -- A proper build of LuaRocks will hardcode the system
+   -- and proc values with hardcoded.SYSTEM and hardcoded.PROCESSOR.
+   -- If that is not available, we try to identify the system.
+   local system, processor = sysdetect.detect()
+   if hardcoded.SYSTEM then
+      system = hardcoded.SYSTEM
+   end
+   if hardcoded.PROCESSOR then
+      processor = hardcoded.PROCESSOR
+   end
+
+   if system == "windows" then
+      if os.getenv("VCINSTALLDIR") then
+         -- running from the Development Command prompt for VS 2017
+         system = "windows"
+      else
+         local msystem = os.getenv("MSYSTEM")
+         if msystem == nil then
+            system = "mingw"
+         elseif msystem == "MSYS" then
+            system = "msys"
+         else
+            -- MINGW32 or MINGW64
+            system = "msys2_mingw_w64"
+         end
+      end
+   end
+
+   cfg.target_cpu = processor
+
+   local platforms = make_platforms(system)
+
+   ----------------------------------------
+   -- Platform is determined.
+   -- Let's load the config files.
+   ----------------------------------------
+
+   local sys_config_file
+   local home_config_file
+   local project_config_file
+
+   local config_file_name = "config-"..cfg.lua_version..".lua"
+
+   do
+      local sysconfdir = os.getenv("LUAROCKS_SYSCONFDIR") or hardcoded.SYSCONFDIR
+      if platforms.windows and not platforms.msys2_mingw_w64 then
+         cfg.home = os.getenv("APPDATA") or "c:"
+         cfg.home_tree = dir.path(cfg.home, "luarocks")
+         cfg.sysconfdir = sysconfdir or dir.path((os.getenv("PROGRAMFILES") or "c:"), "luarocks")
+      else
+         cfg.home = os.getenv("HOME") or ""
+         cfg.home_tree = dir.path(cfg.home, ".luarocks")
+         cfg.sysconfdir = sysconfdir or detect_sysconfdir() or "/etc/luarocks"
+      end
+   end
+
+   -- Load system configuration file
+   sys_config_file = dir.path(cfg.sysconfdir, config_file_name)
+   local sys_config_ok, err = load_config_file(cfg, platforms, sys_config_file)
+   if err then
+      exit_ok, exit_err, exit_what = nil, err, "config"
+   end
+
+   -- Load user configuration file (if allowed)
+   local home_config_ok
+   local project_config_ok
+   if not hardcoded.FORCE_CONFIG then
+      local env_var   = "LUAROCKS_CONFIG_" .. cfg.lua_version:gsub("%.", "_")
+      local env_value = os.getenv(env_var)
+      if not env_value then
+         env_var   = "LUAROCKS_CONFIG"
+         env_value = os.getenv(env_var)
+      end
+      -- first try environment provided file, so we can explicitly warn when it is missing
+      if env_value then
+         local env_ok, err = load_config_file(cfg, platforms, env_value)
+         if err then
+            exit_ok, exit_err, exit_what = nil, err, "config"
+         elseif warning and not env_ok then
+            warning("Warning: could not load configuration file `"..env_value.."` given in environment variable "..env_var.."\n")
+         end
+         if env_ok then
+            home_config_ok = true
+            home_config_file = env_value
+         end
+      end
+
+      -- try XDG config home
+      if platforms.unix and not home_config_ok then
+         local xdg_config_home = os.getenv("XDG_CONFIG_HOME") or dir.path(cfg.home, ".config")
+         cfg.homeconfdir = dir.path(xdg_config_home, "luarocks")
+         home_config_file = dir.path(cfg.homeconfdir, config_file_name)
+         home_config_ok, err = load_config_file(cfg, platforms, home_config_file)
+         if err then
+            exit_ok, exit_err, exit_what = nil, err, "config"
+         end
+      end
+
+      -- try the alternative defaults if there was no environment specified file or it didn't work
+      if not home_config_ok then
+         cfg.homeconfdir = cfg.home_tree
+         home_config_file = dir.path(cfg.homeconfdir, config_file_name)
+         home_config_ok, err = load_config_file(cfg, platforms, home_config_file)
+         if err then
+            exit_ok, exit_err, exit_what = nil, err, "config"
+         end
+      end
+
+      -- finally, use the project-specific config file if any
+      if cfg.project_dir then
+         project_config_file = dir.path(cfg.project_dir, ".luarocks", config_file_name)
+         project_config_ok, err = load_config_file(cfg, platforms, project_config_file)
+         if err then
+            exit_ok, exit_err, exit_what = nil, err, "config"
+         end
+      end
+   end
+
+   -- backwards compatibility:
+   if cfg.lua_interpreter and cfg.variables.LUA_BINDIR and not cfg.variables.LUA then
+      cfg.variables.LUA = dir.path(cfg.variables.LUA_BINDIR, cfg.lua_interpreter)
+   end
+
+   ----------------------------------------
+   -- Config files are loaded.
+   -- Let's finish up the cfg table.
+   ----------------------------------------
+
+   -- Settings given via the CLI (i.e. --lua-dir) take precedence over config files.
+   cfg.project_dir = detected.given_project_dir or cfg.project_dir
+   cfg.lua_version = detected.given_lua_version or cfg.lua_version
+   if detected.given_lua_dir then
+      cfg.variables.LUA = detected.lua
+      cfg.variables.LUA_DIR = detected.given_lua_dir
+      cfg.variables.LUA_BINDIR = detected.lua_bindir
+      cfg.variables.LUA_LIBDIR = nil
+      cfg.variables.LUA_INCDIR = nil
+   end
+
+   -- Build a default list of rocks trees if not given
+   if cfg.rocks_trees == nil then
+      cfg.rocks_trees = {}
+      if cfg.home_tree then
+         table.insert(cfg.rocks_trees, { name = "user", root = cfg.home_tree } )
+      end
+      if hardcoded.PREFIX and hardcoded.PREFIX ~= cfg.home_tree then
+         table.insert(cfg.rocks_trees, { name = "system", root = hardcoded.PREFIX } )
+      end
+   end
+
+   local defaults = make_defaults(cfg.lua_version, processor, platforms, cfg.home)
+
+   if platforms.windows and hardcoded.WIN_TOOLS then
+      local tools = { "SEVENZ", "CP", "FIND", "LS", "MD5SUM", "WGET", }
+      for _, tool in ipairs(tools) do
+         defaults.variables[tool] = '"' .. dir.path(hardcoded.WIN_TOOLS, defaults.variables[tool] .. '.exe') .. '"'
+      end
+   else
+      defaults.fs_use_modules = true
+   end
+
+   -- if only cfg.variables.LUA is given in config files,
+   -- derive LUA_BINDIR and LUA_DIR from them.
+   if cfg.variables.LUA and not cfg.variables.LUA_BINDIR then
+      cfg.variables.LUA_BINDIR = cfg.variables.LUA:match("^(.*)[\\/][^\\/]*$")
+      if not cfg.variables.LUA_DIR then
+         cfg.variables.LUA_DIR = cfg.variables.LUA_BINDIR:gsub("[\\/]bin$", "") or cfg.variables.LUA_BINDIR
+      end
+   end
+
+   use_defaults(cfg, defaults)
+
+   cfg.user_agent = "LuaRocks/"..cfg.program_version.." "..cfg.arch
+
+   cfg.config_files = {
+      project = cfg.project_dir and {
+         file = project_config_file,
+         found = not not project_config_ok,
+      },
+      system = {
+         file = sys_config_file,
+         found = not not sys_config_ok,
+      },
+      user = {
+         file = home_config_file,
+         found = not not home_config_ok,
+      },
+      nearest = project_config_ok
+                and project_config_file
+                or (home_config_ok
+                    and home_config_file
+                    or sys_config_file),
+   }
+
+   cfg.cache = {}
+
+   ----------------------------------------
+   -- Attributes of cfg are set.
+   -- Let's add some methods.
+   ----------------------------------------
+
+   do
+      local function make_paths_from_tree(tree)
+         local lua_path, lib_path, bin_path
+         if type(tree) == "string" then
+            lua_path = dir.path(tree, cfg.lua_modules_path)
+            lib_path = dir.path(tree, cfg.lib_modules_path)
+            bin_path = dir.path(tree, "bin")
+         else
+            lua_path = tree.lua_dir or dir.path(tree.root, cfg.lua_modules_path)
+            lib_path = tree.lib_dir or dir.path(tree.root, cfg.lib_modules_path)
+            bin_path = tree.bin_dir or dir.path(tree.root, "bin")
+         end
+         return lua_path, lib_path, bin_path
+      end
+
+      function cfg.package_paths(current)
+         local new_path, new_cpath, new_bin = {}, {}, {}
+         local function add_tree_to_paths(tree)
+            local lua_path, lib_path, bin_path = make_paths_from_tree(tree)
+            table.insert(new_path,  dir.path(lua_path, "?.lua"))
+            table.insert(new_path,  dir.path(lua_path, "?", "init.lua"))
+            table.insert(new_cpath, dir.path(lib_path, "?."..cfg.lib_extension))
+            table.insert(new_bin, bin_path)
+         end
+         if current then
+            add_tree_to_paths(current)
+         end
+         for _,tree in ipairs(cfg.rocks_trees) do
+            add_tree_to_paths(tree)
+         end
+         return table.concat(new_path, ";"), table.concat(new_cpath, ";"), table.concat(new_bin, cfg.export_path_separator)
+      end
+   end
+
+   function cfg.init_package_paths()
+      local lr_path, lr_cpath, lr_bin = cfg.package_paths()
+      package.path = util.cleanup_path(package.path .. ";" .. lr_path, ";", cfg.lua_version, true)
+      package.cpath = util.cleanup_path(package.cpath .. ";" .. lr_cpath, ";", cfg.lua_version, true)
+   end
+
+   --- Check if platform was detected
+   -- @param name string: The platform name to check.
+   -- @return boolean: true if LuaRocks is currently running on queried platform.
+   function cfg.is_platform(name)
+      assert(type(name) == "string")
+      return platforms[name]
+   end
+
+   -- @param direction (optional) "least-specific-first" (default) or "most-specific-first"
+   function cfg.each_platform(direction)
+      direction = direction or "least-specific-first"
+      local i, delta
+      if direction == "least-specific-first" then
+         i = 0
+         delta = 1
+      else
+         i = #platform_order + 1
+         delta = -1
+      end
+      return function()
+         local p
+         repeat
+            i = i + delta
+            p = platform_order[i]
+         until (not p) or platforms[p]
+         return p
+      end
+   end
+
+   function cfg.print_platforms()
+      local platform_keys = {}
+      for k,_ in pairs(platforms) do
+         table.insert(platform_keys, k)
+      end
+      table.sort(platform_keys)
+      return table.concat(platform_keys, ", ")
+   end
+
+   return exit_ok, exit_err, exit_what
+end
+
+return cfg
diff --git a/src/luarocks/core/cfg.lua b/src/luarocks/core/cfg-original.lua
index 6d8fe55b..6d8fe55b 100644
--- a/src/luarocks/core/cfg.lua
+++ b/src/luarocks/core/cfg-original.lua
diff --git a/src/luarocks/core/cfg.tl b/src/luarocks/core/cfg.tl
new file mode 100644
index 00000000..77605554
--- /dev/null
+++ b/src/luarocks/core/cfg.tl
@@ -0,0 +1,981 @@
+
+--- Configuration for LuaRocks.
+-- Tries to load the user's configuration file and
+-- defines defaults for unset values. See the
+-- <a href="http://luarocks.org/en/Config_file_format">config
+-- file format documentation</a> for details.
+--
+-- End-users shouldn't edit this file. They can override any defaults
+-- set in this file using their system-wide or user-specific configuration
+-- files. Run `luarocks` with no arguments to see the locations of
+-- these files in your platform.
+
+local table, pairs, require, os, pcall, ipairs, package, type, assert = --!
+      table, pairs, require, os, pcall, ipairs, package, type, assert
+
+local dir = require("luarocks.core.dir") --!
+local util = require("luarocks.core.util")
+local persist = require("luarocks.core.persist")
+local sysdetect = require("luarocks.core.sysdetect")
+local vers = require("luarocks.core.vers")
+
+local record cfg
+
+end
+
+--------------------------------------------------------------------------------
+
+local program_version = "dev" --!
+
+local is_windows = package.config:sub(1,1) == "\\" --!
+
+-- Set order for platform overrides.
+-- More general platform identifiers should be listed first,
+-- more specific ones later.
+local platform_order = {
+   -- Unixes
+   "unix",
+   "bsd",
+   "solaris",
+   "netbsd",
+   "openbsd",
+   "freebsd",
+   "dragonfly",
+   "linux",
+   "macosx",
+   "cygwin",
+   "msys",
+   "haiku",
+   -- Windows
+   "windows",
+   "win32",
+   "mingw",
+   "mingw32",
+   "msys2_mingw_w64",
+}
+
+local type Config = record --!
+   home: any
+   lua_version: any
+   target_cpu: any
+   variables: {any: any}
+   os_getenv: any
+   rocks_trees: any
+   rocks_servers: any
+   check_certificates: any
+   dump_env: function()
+end
+
+local function detect_sysconfdir()
+   if not debug then
+      return
+   end
+   local src = debug.getinfo(1, "S").source
+   if not src then
+      return
+   end
+   src = dir.normalize(src)
+   if src:sub(1, 1) == "@" then
+      src = src:sub(2)
+   end
+   local basedir = src:match("^(.*)[\\/]luarocks[\\/]core[\\/]cfg.lua$")
+   if not basedir then
+      return
+   end
+   -- If installed in a Unix-like tree, use a Unix-like sysconfdir
+   local installdir = basedir:match("^(.*)[\\/]share[\\/]lua[\\/][^/]*$")
+   if installdir then
+      if installdir == "/usr" then
+         return "/etc/luarocks" --!
+      end
+      return dir.path(installdir, "etc", "luarocks")
+   end
+   -- Otherwise, use base directory of sources
+   return basedir
+end
+
+-- local load_config_file --!
+do
+   -- Create global environment for the config files;
+   local function env_for_config_file(cfg: Config, platforms: {any: any}): {any: any} --!
+      local platforms_copy = {}
+      for k,v in pairs(platforms) do
+         platforms_copy[k] = v
+      end
+
+      local e: {any: any} --!
+      e = {
+         home = cfg.home,
+         lua_version = cfg.lua_version,
+         platforms = platforms_copy,
+         processor = cfg.target_cpu,   -- remains for compat reasons
+         target_cpu = cfg.target_cpu,  -- replaces `processor`
+         os_getenv = os.getenv,
+         variables = cfg.variables or {},
+         dump_env = function()
+            -- debug function, calling it from a config file will show all
+            -- available globals to that config file
+            print(util.show_table(e, "global environment"))
+         end,
+      }
+      return e
+   end
+
+   -- Merge values from config files read into the `cfg` table
+   local function merge_overrides(cfg: Config, overrides: Config)
+      -- remove some stuff we do not want to integrate
+      overrides.os_getenv = nil
+      overrides.dump_env = nil
+      -- remove tables to be copied verbatim instead of deeply merged
+      if overrides.rocks_trees   then cfg.rocks_trees   = nil end
+      if overrides.rocks_servers then cfg.rocks_servers = nil end
+      -- perform actual merge
+      util.deep_merge(cfg, overrides)
+   end
+
+   local function update_platforms(platforms: {any: any}, overrides: {any: any})
+      if overrides[1] then
+         for k, _ in pairs(platforms) do
+            platforms[k] = nil
+         end
+         for _, v in ipairs(overrides) do
+            platforms[v] = true
+         end
+         -- set some fallback default in case the user provides an incomplete configuration.
+         -- LuaRocks expects a set of defaults to be available.
+         if not (platforms.unix or platforms.windows) then
+            platforms[is_windows and "windows" or "unix"] = true
+         end
+      end
+   end
+
+   -- Load config file and merge its contents into the `cfg` module table.
+   -- @return filepath of successfully loaded file or nil if it failed
+   local load_config_file = function(cfg: Config, platforms: {any: any}, filepath: string): string --!
+      local result, err, errcode = persist.load_into_table(filepath, env_for_config_file(cfg, platforms))
+      if (not result) and errcode ~= "open" then
+         -- errcode is either "load" or "run"; bad config file, so error out
+         return nil, err, "config"
+      end
+      if result then
+         -- success in loading and running, merge contents and exit
+         update_platforms(platforms, result.platforms)
+         result.platforms = nil
+         merge_overrides(cfg, result)
+         return filepath
+      end
+      return nil -- nothing was loaded
+   end
+end
+
+local platform_sets = {
+   freebsd = { unix = true, bsd = true, freebsd = true },
+   openbsd = { unix = true, bsd = true, openbsd = true },
+   dragonfly = { unix = true, bsd = true, dragonfly = true },
+   solaris = { unix = true, solaris = true },
+   windows = { windows = true, win32 = true },
+   cygwin = { unix = true, cygwin = true },
+   macosx = { unix = true, bsd = true, macosx = true, macos = true },
+   netbsd = { unix = true, bsd = true, netbsd = true },
+   haiku = { unix = true, haiku = true },
+   linux = { unix = true, linux = true },
+   mingw = { windows = true, win32 = true, mingw32 = true, mingw = true },
+   msys = { unix = true, cygwin = true, msys = true },
+   msys2_mingw_w64 = { windows = true, win32 = true, mingw32 = true, mingw = true, msys = true, msys2_mingw_w64 = true },
+}
+
+local function make_platforms(system: string): {any: boolean} --! :System
+   -- fallback to Unix in unknown systems
+   return platform_sets[system] or { unix = true }
+end
+
+--------------------------------------------------------------------------------
+
+local function make_defaults(lua_version: string, target_cpu: string, platforms: {any: any}, home: string): {any: any} --!
+
+   -- Configure defaults:
+   local defaults = {
+
+      local_by_default = false,
+      accept_unknown_fields = false,
+      fs_use_modules = true,
+      hooks_enabled = true,
+      deps_mode = "one",
+      no_manifest = false,
+      check_certificates = false,
+
+      cache_timeout = 60,
+      cache_fail_timeout = 86400,
+
+      lua_modules_path = dir.path("share", "lua", lua_version),
+      lib_modules_path = dir.path("lib", "lua", lua_version),
+      rocks_subdir = dir.path("lib", "luarocks", "rocks-"..lua_version),
+
+      arch = "unknown",
+      lib_extension = "unknown",
+      external_lib_extension = "unknown", --?
+      static_lib_extension = "unknown", --?
+      obj_extension = "unknown",
+      link_lua_explicitly = false,
+
+      external_deps_dirs = {}, --?
+      external_deps_patterns: {string} = {}, --?
+      runtime_external_deps_patterns: {string} = {}, --?
+
+      export_path_separator = "", --?
+      wrapper_suffix = "", --?
+
+
+      rocks_servers = {
+         {
+           "https://luarocks.org",
+           "https://raw.githubusercontent.com/rocks-moonscript-org/moonrocks-mirror/master/",
+           "https://loadk.com/luarocks/",
+         }
+      },
+      disabled_servers = {},
+
+      upload = {
+         server = "https://luarocks.org",
+         tool_version = "1.0.0",
+         api_version = "1",
+      },
+
+      lua_extension = "lua",
+      connection_timeout = 30,  -- 0 = no timeout
+
+      makefile = "", --?
+      local_cache = "", --? "" | {""}
+      web_browser = "", --? "" | {""}
+      cmake_generator = "", --?
+      gcc_rpath = false, --?
+
+      variables = {
+         MAKE = os.getenv("MAKE") or "make",
+         CC = os.getenv("CC") or "cc",
+         LD = os.getenv("CC") or "ld",
+         AR = os.getenv("AR") or "ar",
+         RANLIB = os.getenv("RANLIB") or "ranlib",
+
+         CVS = "cvs",
+         GIT = "git",
+         SSCM = "sscm",
+         SVN = "svn",
+         HG = "hg",
+
+         GPG = "gpg",
+
+         RSYNC = "rsync",
+         WGET = "wget",
+         SCP = "scp",
+         CURL = "curl",
+
+         PWD = "pwd",
+         MKDIR = "mkdir",
+         RMDIR = "rmdir",
+         CP = "cp",
+         LN = "ln",
+         LS = "ls",
+         RM = "rm",
+         FIND = "find",
+         CHMOD = "chmod",
+         ICACLS = "icacls",
+         MKTEMP = "mktemp",
+
+         ZIP = "zip",
+         UNZIP = "unzip -n",
+         GUNZIP = "gunzip",
+         BUNZIP2 = "bunzip2",
+         TAR = "tar",
+
+         MD5SUM = "md5sum",
+         OPENSSL = "openssl",
+         MD5 = "md5",
+         TOUCH = "touch",
+
+         CMAKE = "cmake",
+         SEVENZ = "7z",
+
+         RSYNCFLAGS = "--exclude=.git -Oavz",
+         CURLNOCERTFLAG = "",
+         WGETNOCERTFLAG = "",
+
+         RC = "", --?
+         MT = "", --?
+         CFLAGS = "", --?
+         LDFLAGS = "", --?
+         LIBFLAG = "", --?
+         TEST = "", --?
+         LIB_EXTENSION = "", --?
+         OBJ_EXTENSION = "", --?
+      },
+
+      external_deps_subdirs = {
+         bin = "bin",
+         lib = "lib",
+         include = "include"
+      },
+      runtime_external_deps_subdirs = {
+         bin = "bin",
+         lib = "lib",
+         include = "include"
+      },
+   }
+
+   if platforms.windows then
+
+      defaults.arch = "win32-"..target_cpu
+      defaults.lib_extension = "dll"
+      defaults.external_lib_extension = "dll"
+      defaults.static_lib_extension = "lib"
+      defaults.obj_extension = "obj"
+      defaults.external_deps_dirs = {
+         dir.path("c:", "external"),
+         dir.path("c:", "windows", "system32"),
+      }
+
+      defaults.makefile = "Makefile.win"
+      defaults.variables.PWD = "echo %cd%"
+      defaults.variables.MKDIR = "md"
+      defaults.variables.MAKE = os.getenv("MAKE") or "nmake"
+      defaults.variables.CC = os.getenv("CC") or "cl"
+      defaults.variables.RC = os.getenv("WINDRES") or "rc"
+      defaults.variables.LD = os.getenv("LINK") or "link"
+      defaults.variables.MT = os.getenv("MT") or "mt"
+      defaults.variables.AR = os.getenv("AR") or "lib"
+      defaults.variables.CFLAGS = os.getenv("CFLAGS") or "/nologo /MD /O2"
+      defaults.variables.LDFLAGS = os.getenv("LDFLAGS")
+      defaults.variables.LIBFLAG = "/nologo /dll"
+
+      defaults.external_deps_patterns = {
+         bin = { "?.exe", "?.bat" },
+         lib = { "?.lib", "lib?.lib", "?.dll", "lib?.dll" },
+         include = { "?.h" }
+      }
+      defaults.runtime_external_deps_patterns = {
+         bin = { "?.exe", "?.bat" },
+         lib = { "?.dll", "lib?.dll" },
+         include = { "?.h" }
+      }
+      defaults.export_path_separator = ";"
+      defaults.wrapper_suffix = ".bat"
+
+      local localappdata = os.getenv("LOCALAPPDATA")
+      if not localappdata then
+         -- for Windows versions below Vista
+         localappdata = dir.path((os.getenv("USERPROFILE") or dir.path("c:", "Users", "All Users")), "Local Settings", "Application Data")
+      end
+      defaults.local_cache = dir.path(localappdata, "LuaRocks", "Cache")
+      defaults.web_browser = "start"
+
+      defaults.external_deps_subdirs.lib = { "lib", "", "bin" }
+      defaults.runtime_external_deps_subdirs.lib = { "lib", "", "bin" }
+      defaults.link_lua_explicitly = true
+      defaults.fs_use_modules = false
+   end
+
+   if platforms.mingw32 then
+      defaults.obj_extension = "o"
+      defaults.static_lib_extension = "a"
+      defaults.external_deps_dirs = {
+         dir.path("c:", "external"),
+         dir.path("c:", "mingw"),
+         dir.path("c:", "windows", "system32"),
+      }
+      defaults.cmake_generator = "MinGW Makefiles"
+      defaults.variables.MAKE = os.getenv("MAKE") or "mingw32-make"
+      if target_cpu == "x86_64" then
+         defaults.variables.CC = os.getenv("CC") or "x86_64-w64-mingw32-gcc"
+         defaults.variables.LD = os.getenv("CC") or "x86_64-w64-mingw32-gcc"
+      else
+         defaults.variables.CC = os.getenv("CC") or "mingw32-gcc"
+         defaults.variables.LD = os.getenv("CC") or "mingw32-gcc"
+      end
+      defaults.variables.AR = os.getenv("AR") or "ar"
+      defaults.variables.RC = os.getenv("WINDRES") or "windres"
+      defaults.variables.RANLIB = os.getenv("RANLIB") or "ranlib"
+      defaults.variables.CFLAGS = os.getenv("CFLAGS") or "-O2"
+      defaults.variables.LDFLAGS = os.getenv("LDFLAGS")
+      defaults.variables.LIBFLAG = "-shared"
+      defaults.makefile = "Makefile"
+      defaults.external_deps_patterns = {
+         bin = { "?.exe", "?.bat" },
+         -- mingw lookup list from http://stackoverflow.com/a/15853231/1793220
+         -- ...should we keep ?.lib at the end? It's not in the above list.
+         lib = { "lib?.dll.a", "?.dll.a", "lib?.a", "cyg?.dll", "lib?.dll", "?.dll", "?.lib" },
+         include = { "?.h" }
+      }
+      defaults.runtime_external_deps_patterns = {
+         bin = { "?.exe", "?.bat" },
+         lib = { "cyg?.dll", "?.dll", "lib?.dll" },
+         include = { "?.h" }
+      }
+      defaults.link_lua_explicitly = true
+   end
+
+   if platforms.unix then
+      defaults.lib_extension = "so"
+      defaults.static_lib_extension = "a"
+      defaults.external_lib_extension = "so"
+      defaults.obj_extension = "o"
+      defaults.external_deps_dirs = { "/usr/local", "/usr", "/" }
+
+      defaults.variables.CFLAGS = os.getenv("CFLAGS") or "-O2"
+      -- we pass -fPIC via CFLAGS because of old Makefile-based Lua projects
+      -- which didn't have -fPIC in their Makefiles but which honor CFLAGS
+      if not defaults.variables.CFLAGS:match("-fPIC") then
+         defaults.variables.CFLAGS = defaults.variables.CFLAGS.." -fPIC"
+      end
+
+      defaults.variables.LDFLAGS = os.getenv("LDFLAGS")
+
+      defaults.cmake_generator = "Unix Makefiles"
+      defaults.variables.CC = os.getenv("CC") or "gcc"
+      defaults.variables.LD = os.getenv("CC") or "gcc"
+      defaults.gcc_rpath = true
+      defaults.variables.LIBFLAG = "-shared"
+      defaults.variables.TEST = "test"
+
+      defaults.external_deps_patterns = {
+         bin = { "?" },
+         lib = { "lib?.a", "lib?.so", "lib?.so.*" },
+         include = { "?.h" }
+      }
+      defaults.runtime_external_deps_patterns = {
+         bin = { "?" },
+         lib = { "lib?.so", "lib?.so.*" },
+         include = { "?.h" }
+      }
+      defaults.export_path_separator = ":"
+      defaults.wrapper_suffix = ""
+      local xdg_cache_home = os.getenv("XDG_CACHE_HOME") or home.."/.cache"
+      defaults.local_cache = xdg_cache_home.."/luarocks"
+      defaults.web_browser = "xdg-open"
+   end
+
+   if platforms.cygwin then
+      defaults.lib_extension = "so" -- can be overridden in the config file for mingw builds
+      defaults.arch = "cygwin-"..target_cpu
+      defaults.cmake_generator = "Unix Makefiles"
+      defaults.variables.CC = "echo -llua | xargs " .. (os.getenv("CC") or "gcc")
+      defaults.variables.LD = "echo -llua | xargs " .. (os.getenv("CC") or "gcc")
+      defaults.variables.LIBFLAG = "-shared"
+      defaults.link_lua_explicitly = true
+   end
+
+   if platforms.msys then
+      -- msys is basically cygwin made out of mingw, meaning the subsytem is unixish
+      -- enough, yet we can freely mix with native win32
+      defaults.external_deps_patterns = {
+         bin = { "?.exe", "?.bat", "?" },
+         lib = { "lib?.so", "lib?.so.*", "lib?.dll.a", "?.dll.a",
+                 "lib?.a", "lib?.dll", "?.dll", "?.lib" },
+         include = { "?.h" }
+      }
+      defaults.runtime_external_deps_patterns = {
+         bin = { "?.exe", "?.bat" },
+         lib = { "lib?.so", "?.dll", "lib?.dll" },
+         include = { "?.h" }
+      }
+      if platforms.mingw then
+         -- MSYS2 can build Windows programs that depend on
+         -- msys-2.0.dll (based on Cygwin) but MSYS2 is also designed
+         -- for building native Windows programs by MinGW. These
+         -- programs don't depend on msys-2.0.dll.
+         local pipe = io.popen("cygpath --windows %MINGW_PREFIX%")
+         local mingw_prefix = pipe:read("*l")
+         pipe:close()
+         defaults.external_deps_dirs = {
+            mingw_prefix,
+            dir.path("c:", "windows", "system32"),
+         }
+         defaults.makefile = "Makefile"
+         defaults.cmake_generator = "MSYS Makefiles"
+         defaults.local_cache = dir.path(home, ".cache", "luarocks")
+         defaults.variables.MAKE = os.getenv("MAKE") or "make"
+         defaults.variables.CC = os.getenv("CC") or "gcc"
+         defaults.variables.RC = os.getenv("WINDRES") or "windres"
+         defaults.variables.LD = os.getenv("CC") or "gcc"
+         defaults.variables.MT = os.getenv("MT") or nil
+         defaults.variables.AR = os.getenv("AR") or "ar"
+         defaults.variables.RANLIB = os.getenv("RANLIB") or "ranlib"
+
+         defaults.variables.CFLAGS = os.getenv("CFLAGS") or "-O2 -fPIC"
+         if not defaults.variables.CFLAGS:match("-fPIC") then
+            defaults.variables.CFLAGS = defaults.variables.CFLAGS.." -fPIC"
+         end
+
+         defaults.variables.LIBFLAG = "-shared"
+      end
+   end
+
+   if platforms.bsd then
+      defaults.variables.MAKE = "gmake"
+      defaults.gcc_rpath = false
+      defaults.variables.CC = os.getenv("CC") or "cc"
+      defaults.variables.LD = os.getenv("CC") or defaults.variables.CC
+   end
+
+   if platforms.macosx then
+      defaults.variables.MAKE = os.getenv("MAKE") or "make"
+      defaults.external_lib_extension = "dylib"
+      defaults.arch = "macosx-"..target_cpu
+      defaults.variables.LIBFLAG = "-bundle -undefined dynamic_lookup -all_load"
+      local version = util.popen_read("sw_vers -productVersion")
+      if not (version:match("^%d+%.%d+%.%d+$") or version:match("^%d+%.%d+$")) then
+         version = "10.3"
+      end
+      version = vers.parse_version(version)
+      if version >= vers.parse_version("11.0") then
+         version = vers.parse_version("11.0")
+      elseif version >= vers.parse_version("10.10") then
+         version = vers.parse_version("10.8")
+      elseif version >= vers.parse_version("10.5") then
+         version = vers.parse_version("10.5")
+      else
+         defaults.gcc_rpath = false
+      end
+      defaults.variables.CC = "env MACOSX_DEPLOYMENT_TARGET="..tostring(version).." gcc"
+      defaults.variables.LD = "env MACOSX_DEPLOYMENT_TARGET="..tostring(version).." gcc"
+      defaults.web_browser = "open"
+
+      -- XCode SDK
+      local sdk_path = util.popen_read("xcrun --show-sdk-path 2>/dev/null")
+      if sdk_path then
+         table.insert(defaults.external_deps_dirs, sdk_path .. "/usr")
+         table.insert(defaults.external_deps_patterns.lib, 1, "lib?.tbd")
+         table.insert(defaults.runtime_external_deps_patterns.lib, 1, "lib?.tbd")
+      end
+
+      -- Homebrew
+      table.insert(defaults.external_deps_dirs, "/usr/local/opt")
+      defaults.external_deps_subdirs.lib = { "lib", "" }
+      defaults.runtime_external_deps_subdirs.lib = { "lib", "" }
+      table.insert(defaults.external_deps_patterns.lib, 1, "/?/lib/lib?.dylib")
+      table.insert(defaults.runtime_external_deps_patterns.lib, 1, "/?/lib/lib?.dylib")
+   end
+
+   if platforms.linux then
+      defaults.arch = "linux-"..target_cpu
+
+      local gcc_arch = util.popen_read("gcc -print-multiarch 2>/dev/null")
+      if gcc_arch and gcc_arch ~= "" then
+         defaults.external_deps_subdirs.lib = { "lib/" .. gcc_arch, "lib64", "lib" }
+         defaults.runtime_external_deps_subdirs.lib = { "lib/" .. gcc_arch, "lib64", "lib" }
+      else
+         defaults.external_deps_subdirs.lib = { "lib64", "lib" }
+         defaults.runtime_external_deps_subdirs.lib = { "lib64", "lib" }
+      end
+   end
+
+   if platforms.freebsd then
+      defaults.arch = "freebsd-"..target_cpu
+   elseif platforms.dragonfly then
+      defaults.arch = "dragonfly-"..target_cpu
+   elseif platforms.openbsd then
+      defaults.arch = "openbsd-"..target_cpu
+   elseif platforms.netbsd then
+      defaults.arch = "netbsd-"..target_cpu
+   elseif platforms.solaris then
+      defaults.arch = "solaris-"..target_cpu
+      defaults.variables.MAKE = "gmake"
+   end
+
+   -- Expose some more values detected by LuaRocks for use by rockspec authors.
+   defaults.variables.LIB_EXTENSION = defaults.lib_extension
+   defaults.variables.OBJ_EXTENSION = defaults.obj_extension
+
+   return defaults
+end
+
+local function use_defaults(cfg: Config, defaults: Config) --!
+
+   -- Populate variables with values from their 'defaults' counterparts
+   -- if they were not already set by user.
+   if not cfg.variables then
+      cfg.variables = {}
+   end
+   for k,v in pairs(defaults.variables) do
+      if not cfg.variables[k] then
+         cfg.variables[k] = v
+      end
+   end
+
+   util.deep_merge_under(cfg, defaults)
+
+   -- FIXME get rid of this
+   if not cfg.check_certificates then
+      cfg.variables.CURLNOCERTFLAG = "-k"
+      cfg.variables.WGETNOCERTFLAG = "--no-check-certificate"
+   end
+end
+
+--------------------------------------------------------------------------------
+
+local cfg = {}
+
+--- Initializes the LuaRocks configuration for variables, paths
+-- and OS detection.
+-- @param detected table containing information detected about the
+-- environment. All fields below are optional:
+-- * lua_version (in x.y format, e.g. "5.3")
+-- * lua_bindir (e.g. "/usr/local/bin")
+-- * lua_dir (e.g. "/usr/local")
+-- * lua (e.g. "/usr/local/bin/lua-5.3")
+-- * project_dir (a string with the path of the project directory
+--   when using per-project environments, as created with `luarocks init`)
+-- @param warning a logging function for warnings that takes a string
+-- @return true on success; nil and an error message on failure.
+function cfg.init(detected: {any: any}, warning: function(string)): nil, string, string --!
+   detected = detected or {}
+
+   local exit_ok = true
+   local exit_err = nil
+   local exit_what = nil
+
+   local hc_ok, hardcoded = pcall(require, "luarocks.core.hardcoded")
+   if not hc_ok then
+      hardcoded = {}
+   end
+
+   local init = cfg.init
+
+   ----------------------------------------
+   -- Reset the cfg table.
+   ----------------------------------------
+
+   for k, _ in pairs(cfg) do
+      cfg[k] = nil
+   end
+
+   cfg.program_version = program_version
+
+   if hardcoded.IS_BINARY then
+      cfg.is_binary = true
+   end
+
+   -- Use detected values as defaults, overridable via config files or CLI args
+
+   local hardcoded_lua = hardcoded.LUA
+   local hardcoded_lua_dir = hardcoded.LUA_DIR
+   local hardcoded_lua_bindir = hardcoded.LUA_BINDIR
+   local hardcoded_lua_incdir = hardcoded.LUA_INCDIR
+   local hardcoded_lua_libdir = hardcoded.LUA_LIBDIR
+   local hardcoded_lua_version = hardcoded.LUA_VERSION or _VERSION:sub(5)
+
+   -- if --lua-version or --lua-dir are passed from the CLI,
+   -- don't use the hardcoded paths at all
+   if detected.given_lua_version or detected.given_lua_dir then
+      hardcoded_lua = nil
+      hardcoded_lua_dir = nil
+      hardcoded_lua_bindir = nil
+      hardcoded_lua_incdir = nil
+      hardcoded_lua_libdir = nil
+      hardcoded_lua_version = nil
+   end
+
+   cfg.lua_version = detected.lua_version or hardcoded_lua_version
+   cfg.project_dir = (not hardcoded.FORCE_CONFIG) and detected.project_dir
+
+   do
+      local lua = detected.lua or hardcoded_lua
+      local lua_dir = detected.lua_dir or hardcoded_lua_dir
+      local lua_bindir = detected.lua_bindir or hardcoded_lua_bindir
+      cfg.variables = {
+         LUA = lua,
+         LUA_DIR = lua_dir,
+         LUA_BINDIR = lua_bindir,
+         LUA_LIBDIR = hardcoded_lua_libdir,
+         LUA_INCDIR = hardcoded_lua_incdir,
+      }
+   end
+
+   cfg.init = init
+
+   ----------------------------------------
+   -- System detection.
+   ----------------------------------------
+
+   -- A proper build of LuaRocks will hardcode the system
+   -- and proc values with hardcoded.SYSTEM and hardcoded.PROCESSOR.
+   -- If that is not available, we try to identify the system.
+   local system, processor = sysdetect.detect()
+   if hardcoded.SYSTEM then
+      system = hardcoded.SYSTEM
+   end
+   if hardcoded.PROCESSOR then
+      processor = hardcoded.PROCESSOR
+   end
+
+   if system == "windows" then
+      if os.getenv("VCINSTALLDIR") then
+         -- running from the Development Command prompt for VS 2017
+         system = "windows"
+      else
+         local msystem = os.getenv("MSYSTEM")
+         if msystem == nil then
+            system = "mingw"
+         elseif msystem == "MSYS" then
+            system = "msys"
+         else
+            -- MINGW32 or MINGW64
+            system = "msys2_mingw_w64"
+         end
+      end
+   end
+
+   cfg.target_cpu = processor
+
+   local platforms = make_platforms(system)
+
+   ----------------------------------------
+   -- Platform is determined.
+   -- Let's load the config files.
+   ----------------------------------------
+
+   local sys_config_file: string --?
+   local home_config_file: string
+   local project_config_file: string
+
+   local config_file_name = "config-"..cfg.lua_version..".lua"
+
+   do
+      local sysconfdir = os.getenv("LUAROCKS_SYSCONFDIR") or hardcoded.SYSCONFDIR
+      if platforms.windows and not platforms.msys2_mingw_w64 then
+         cfg.home = os.getenv("APPDATA") or "c:" --!
+         cfg.home_tree = dir.path(cfg.home, "luarocks") --!
+         cfg.sysconfdir = sysconfdir or dir.path((os.getenv("PROGRAMFILES") or "c:"), "luarocks") --!
+      else
+         cfg.home = os.getenv("HOME") or "" --!
+         cfg.home_tree = dir.path(cfg.home, ".luarocks") --!
+         cfg.sysconfdir = sysconfdir or detect_sysconfdir() or "/etc/luarocks" --!
+      end
+   end
+
+   -- Load system configuration file
+   sys_config_file = dir.path(cfg.sysconfdir, config_file_name)
+   local sys_config_ok, err = load_config_file(cfg, platforms, sys_config_file)
+   if err then
+      exit_ok, exit_err, exit_what = nil, err, "config"
+   end
+
+   -- Load user configuration file (if allowed)
+   local home_config_ok: boolean
+   local project_config_ok: boolean
+   if not hardcoded.FORCE_CONFIG then
+      local env_var   = "LUAROCKS_CONFIG_" .. cfg.lua_version:gsub("%.", "_")
+      local env_value = os.getenv(env_var)
+      if not env_value then
+         env_var   = "LUAROCKS_CONFIG"
+         env_value = os.getenv(env_var)
+      end
+      -- first try environment provided file, so we can explicitly warn when it is missing
+      if env_value then
+         local env_ok, err = load_config_file(cfg, platforms, env_value)
+         if err then
+            exit_ok, exit_err, exit_what = nil, err, "config"
+         elseif warning and not env_ok then
+            warning("Warning: could not load configuration file `"..env_value.."` given in environment variable "..env_var.."\n")
+         end
+         if env_ok then
+            home_config_ok = true
+            home_config_file = env_value
+         end
+      end
+
+      -- try XDG config home
+      if platforms.unix and not home_config_ok then
+         local xdg_config_home = os.getenv("XDG_CONFIG_HOME") or dir.path(cfg.home, ".config")
+         cfg.homeconfdir = dir.path(xdg_config_home, "luarocks")
+         home_config_file = dir.path(cfg.homeconfdir, config_file_name)
+         home_config_ok, err = load_config_file(cfg, platforms, home_config_file)
+         if err then
+            exit_ok, exit_err, exit_what = nil, err, "config"
+         end
+      end
+
+      -- try the alternative defaults if there was no environment specified file or it didn't work
+      if not home_config_ok then
+         cfg.homeconfdir = cfg.home_tree
+         home_config_file = dir.path(cfg.homeconfdir, config_file_name)
+         home_config_ok, err = load_config_file(cfg, platforms, home_config_file)
+         if err then
+            exit_ok, exit_err, exit_what = nil, err, "config"
+         end
+      end
+
+      -- finally, use the project-specific config file if any
+      if cfg.project_dir then
+         project_config_file = dir.path(cfg.project_dir, ".luarocks", config_file_name)
+         project_config_ok, err = load_config_file(cfg, platforms, project_config_file)
+         if err then
+            exit_ok, exit_err, exit_what = nil, err, "config"
+         end
+      end
+   end
+
+   -- backwards compatibility:
+   if cfg.lua_interpreter and cfg.variables.LUA_BINDIR and not cfg.variables.LUA then
+      cfg.variables.LUA = dir.path(cfg.variables.LUA_BINDIR, cfg.lua_interpreter)
+   end
+
+   ----------------------------------------
+   -- Config files are loaded.
+   -- Let's finish up the cfg table.
+   ----------------------------------------
+
+   -- Settings given via the CLI (i.e. --lua-dir) take precedence over config files.
+   cfg.project_dir = detected.given_project_dir or cfg.project_dir
+   cfg.lua_version = detected.given_lua_version or cfg.lua_version
+   if detected.given_lua_dir then
+      cfg.variables.LUA = detected.lua
+      cfg.variables.LUA_DIR = detected.given_lua_dir
+      cfg.variables.LUA_BINDIR = detected.lua_bindir
+      cfg.variables.LUA_LIBDIR = nil
+      cfg.variables.LUA_INCDIR = nil
+   end
+
+   -- Build a default list of rocks trees if not given
+   if cfg.rocks_trees == nil then
+      cfg.rocks_trees = {}
+      if cfg.home_tree then
+         table.insert(cfg.rocks_trees, { name = "user", root = cfg.home_tree } )
+      end
+      if hardcoded.PREFIX and hardcoded.PREFIX ~= cfg.home_tree then
+         table.insert(cfg.rocks_trees, { name = "system", root = hardcoded.PREFIX } )
+      end
+   end
+
+   local defaults = make_defaults(cfg.lua_version, processor, platforms, cfg.home)
+
+   if platforms.windows and hardcoded.WIN_TOOLS then
+      local tools = { "SEVENZ", "CP", "FIND", "LS", "MD5SUM", "WGET", }
+      for _, tool in ipairs(tools) do
+         defaults.variables[tool] = '"' .. dir.path(hardcoded.WIN_TOOLS, defaults.variables[tool] .. '.exe') .. '"'
+      end
+   else
+      defaults.fs_use_modules = true
+   end
+
+   -- if only cfg.variables.LUA is given in config files,
+   -- derive LUA_BINDIR and LUA_DIR from them.
+   if cfg.variables.LUA and not cfg.variables.LUA_BINDIR then
+      cfg.variables.LUA_BINDIR = cfg.variables.LUA:match("^(.*)[\\/][^\\/]*$")
+      if not cfg.variables.LUA_DIR then
+         cfg.variables.LUA_DIR = cfg.variables.LUA_BINDIR:gsub("[\\/]bin$", "") or cfg.variables.LUA_BINDIR
+      end
+   end
+
+   use_defaults(cfg, defaults)
+
+   cfg.user_agent = "LuaRocks/"..cfg.program_version.." "..cfg.arch
+
+   cfg.config_files = {
+      project = cfg.project_dir and {
+         file = project_config_file,
+         found = not not project_config_ok,
+      },
+      system = {
+         file = sys_config_file,
+         found = not not sys_config_ok,
+      },
+      user = {
+         file = home_config_file,
+         found = not not home_config_ok,
+      },
+      nearest = project_config_ok
+                and project_config_file
+                or (home_config_ok
+                    and home_config_file
+                    or sys_config_file),
+   }
+
+   cfg.cache = {}
+
+   ----------------------------------------
+   -- Attributes of cfg are set.
+   -- Let's add some methods.
+   ----------------------------------------
+
+   do
+      local function make_paths_from_tree(tree: {any: string}): string, string, string
+         local lua_path, lib_path, bin_path: string, string, string
+         if type(tree) == "string" then
+            lua_path = dir.path(tree, cfg.lua_modules_path)
+            lib_path = dir.path(tree, cfg.lib_modules_path)
+            bin_path = dir.path(tree, "bin")
+         else
+            lua_path = tree.lua_dir or dir.path(tree.root, cfg.lua_modules_path)
+            lib_path = tree.lib_dir or dir.path(tree.root, cfg.lib_modules_path)
+            bin_path = tree.bin_dir or dir.path(tree.root, "bin")
+         end
+         return lua_path, lib_path, bin_path
+      end
+
+      function cfg.package_paths(current)
+         local new_path, new_cpath, new_bin = {}, {}, {}
+         local function add_tree_to_paths(tree)
+            local lua_path, lib_path, bin_path = make_paths_from_tree(tree)
+            table.insert(new_path,  dir.path(lua_path, "?.lua"))
+            table.insert(new_path,  dir.path(lua_path, "?", "init.lua"))
+            table.insert(new_cpath, dir.path(lib_path, "?."..cfg.lib_extension))
+            table.insert(new_bin, bin_path)
+         end
+         if current then
+            add_tree_to_paths(current)
+         end
+         for _,tree in ipairs(cfg.rocks_trees) do
+            add_tree_to_paths(tree)
+         end
+         return table.concat(new_path, ";"), table.concat(new_cpath, ";"), table.concat(new_bin, cfg.export_path_separator)
+      end
+   end
+
+   function cfg.init_package_paths()
+      local lr_path, lr_cpath, lr_bin = cfg.package_paths()
+      package.path = util.cleanup_path(package.path .. ";" .. lr_path, ";", cfg.lua_version, true)
+      package.cpath = util.cleanup_path(package.cpath .. ";" .. lr_cpath, ";", cfg.lua_version, true)
+   end
+
+   --- Check if platform was detected
+   -- @param name string: The platform name to check.
+   -- @return boolean: true if LuaRocks is currently running on queried platform.
+   function cfg.is_platform(name: string): boolean
+      assert(type(name) == "string")
+      return platforms[name]
+   end
+
+   -- @param direction (optional) "least-specific-first" (default) or "most-specific-first"
+   function cfg.each_platform(direction: string): function(): string
+      direction = direction or "least-specific-first"
+      local i, delta: integer, integer
+      if direction == "least-specific-first" then
+         i = 0
+         delta = 1
+      else
+         i = #platform_order + 1
+         delta = -1
+      end
+      return function()
+         local p: string
+         repeat
+            i = i + delta
+            p = platform_order[i]
+         until (not p) or platforms[p]
+         return p
+      end
+   end
+
+   function cfg.print_platforms(): string
+      local platform_keys = {}
+      for k,_ in pairs(platforms) do
+         table.insert(platform_keys, k)
+      end
+      table.sort(platform_keys)
+      return table.concat(platform_keys, ", ")
+   end
+
+   return exit_ok, exit_err, exit_what
+end
+
+return cfg
\ No newline at end of file