8 files changed, 225 insertions, 34 deletions

diff --git a/spec/cmd_spec.lua b/spec/cmd_spec.lua
index 9067a160..20248af7 100644
--- a/spec/cmd_spec.lua
+++ b/spec/cmd_spec.lua
@@ -56,12 +56,6 @@ describe("LuaRocks command line #integration", function()
          assert.match("malformed", output, 1, true)
       end)
 
-      it("warns but continues if given an invalid version", function()
-         local output = run.luarocks("--lua-version=1.0")
-         assert.match("LUA *: %(not found%)", output)
-         assert.match("Version%s*:%s*1.0", output)
-      end)
-
       it("sets the version independently of project tree", function()
          test_env.run_in_tmp(function(tmpdir)
             assert.truthy(run.luarocks_bool("init --lua-version=" .. test_env.lua_version .. " --lua-versions=" .. test_env.lua_version))
diff --git a/spec/quick/cmd.q b/spec/quick/cmd.q
new file mode 100644
index 00000000..acde92b4
--- /dev/null
+++ b/spec/quick/cmd.q
@@ -0,0 +1,36 @@
+SUITE: luarocks CLI
+
+================================================================================
+TEST: warns but continues if given an invalid version
+
+RUN: luarocks --lua-version 1.0
+
+STDOUT:
+--------------------------------------------------------------------------------
+Version    : 1.0
+LUA        : (interpreter not found)
+--------------------------------------------------------------------------------
+
+
+
+================================================================================
+TEST: reports if lua.h header is not found
+
+RUN: luarocks LUA_INCDIR=/bad/dir
+
+STDOUT:
+--------------------------------------------------------------------------------
+LUA_INCDIR : /bad/dir (lua.h not found)
+--------------------------------------------------------------------------------
+
+
+
+================================================================================
+TEST: reports if Lua library is not found
+
+RUN: luarocks LUA_LIBDIR=/bad/dir
+
+STDOUT:
+--------------------------------------------------------------------------------
+LUA_LIBDIR : /bad/dir (Lua library itself not found)
+--------------------------------------------------------------------------------
diff --git a/spec/quick/config.q b/spec/quick/config.q
index 3150a9ce..d6230567 100644
--- a/spec/quick/config.q
+++ b/spec/quick/config.q
@@ -1,13 +1,11 @@
-================================================================================
-TEST: luarocks config --system-config shows the path of the system config
+SUITE: luarocks config
 
-MKDIR: %{testing_lrprefix}/etc/luarocks
+================================================================================
+TEST: --system-config shows the path of the system config
 
 FILE: %{testing_lrprefix}/etc/luarocks/config-%{LUA_VERSION}.lua
 --------------------------------------------------------------------------------
-
 --------------------------------------------------------------------------------
-
 RUN: luarocks config --system-config
 
 STDOUT:
@@ -15,3 +13,85 @@ STDOUT:
 %{path(%{testing_lrprefix}/etc/luarocks/config-%{LUA_VERSION}.lua)}
 --------------------------------------------------------------------------------
 
+
+
+================================================================================
+TEST: reports when setting a bad LUA_LIBDIR
+
+RUN: luarocks config variables.LUA_LIBDIR /some/bad/path
+
+LuaRocks writes configuration values as they are given, without auto-conversion
+of slashes for Windows:
+
+STDOUT:
+--------------------------------------------------------------------------------
+Wrote
+variables.LUA_LIBDIR = "/some/bad/path"
+--------------------------------------------------------------------------------
+
+STDERR:
+--------------------------------------------------------------------------------
+Warning: Failed finding the Lua library.
+Tried:
+
+LuaRocks may not work correctly when building C modules using this configuration.
+--------------------------------------------------------------------------------
+
+
+
+================================================================================
+TEST: reports when setting a bad LUA_INCDIR
+
+RUN: luarocks config variables.LUA_INCDIR /some/bad/path
+
+STDOUT:
+--------------------------------------------------------------------------------
+Wrote
+variables.LUA_INCDIR = "/some/bad/path"
+--------------------------------------------------------------------------------
+
+LuaRocks uses configuration values as they are given, without auto-conversion
+of slashes for Windows:
+
+STDERR:
+--------------------------------------------------------------------------------
+Warning: Failed finding Lua header lua.h (searched at /some/bad/path). You may need to install Lua development headers.
+
+LuaRocks may not work correctly when building C modules using this configuration.
+--------------------------------------------------------------------------------
+
+
+
+================================================================================
+TEST: rejects setting bad lua_dir
+
+RUN: luarocks config lua_dir /some/bad/dir
+EXIT: 1
+
+STDERR:
+--------------------------------------------------------------------------------
+Lua interpreter not found
+--------------------------------------------------------------------------------
+
+
+
+================================================================================
+TEST: reports when setting a bad LUA_INCDIR
+
+RUN: luarocks config variables.LUA_INCDIR /some/bad/path
+
+STDOUT:
+--------------------------------------------------------------------------------
+Wrote
+variables.LUA_INCDIR = "/some/bad/path"
+--------------------------------------------------------------------------------
+
+LuaRocks uses configuration values as they are given, without auto-conversion
+of slashes for Windows:
+
+STDERR:
+--------------------------------------------------------------------------------
+Warning: Failed finding Lua header lua.h (searched at /some/bad/path). You may need to install Lua development headers.
+
+LuaRocks may not work correctly when building C modules using this configuration.
+--------------------------------------------------------------------------------
diff --git a/spec/util/quick.lua b/spec/util/quick.lua
index cb4bb4cf..c313f575 100644
--- a/spec/util/quick.lua
+++ b/spec/util/quick.lua
@@ -347,7 +347,7 @@ function quick.compile(filename, env)
             write(([=[ ok, err = make_dir(%q) ]=]):format(op.file))
             write(([=[ assert.truthy((lfs.attributes(%q) or {}).mode == "directory", error_message(%d, "MKDIR failed: " .. %q .. " - " .. (err or "") )) ]=]):format(op.file, op.line, op.file))
          elseif op.op == "RUN" then
-            local cmd_helper = cmd_helpers[op.program] or op.program
+            local cmd_helper = cmd_helpers[op.program] or ("%q"):format(op.program)
             local redirs = " 1>stdout.txt 2>stderr.txt "
             write(([=[ local ok, _, code = os.execute(%s .. " " .. %q .. %q) ]=]):format(cmd_helper, op.args, redirs))
             write([=[ if type(ok) == "number" then code = (ok >= 256 and ok / 256 or ok) end ]=])
diff --git a/spec/util/test_env.lua b/spec/util/test_env.lua
index 24a1de9e..8ccb494b 100644
--- a/spec/util/test_env.lua
+++ b/spec/util/test_env.lua
@@ -207,13 +207,16 @@ function test_env.run_in_tmp(f, finally)
    end
    fs.change_dir(tmpdir)
 
-   if finally then
-      finally(function()
-         lfs.chdir(olddir)
-         lfs.rmdir(tmpdir)
-         fs.change_dir(olddir)
-      end)
-   end
+   local lr_config = test_env.env_variables.LUAROCKS_CONFIG
+
+   test_env.copy(lr_config, lr_config .. ".bak")
+
+   finally(function()
+      test_env.copy(lr_config .. ".bak", lr_config)
+      lfs.chdir(olddir)
+      lfs.rmdir(tmpdir)
+      fs.change_dir(olddir)
+   end)
 
    f(tmpdir)
 end
diff --git a/src/luarocks/cmd.lua b/src/luarocks/cmd.lua
index 643023b8..452237d2 100644
--- a/src/luarocks/cmd.lua
+++ b/src/luarocks/cmd.lua
@@ -337,8 +337,8 @@ local lua_example = package.config:sub(1, 1) == "\\"
                     and "<d:\\path\\lua.exe>"
                     or  "</path/lua>"
 
-local function show_status(file, status)
-   return (file and file .. " " or "") .. (status and "(ok)" or "(not found)")
+local function show_status(file, status, err)
+   return (file and file .. " " or "") .. (status and "(ok)" or ("(" .. (err or "not found") ..")"))
 end
 
 local function use_to_fix_location(key, what)
@@ -363,15 +363,15 @@ local function get_config_text(cfg)  -- luacheck: ignore 431
    if cfg.luajit_version then
       buf = buf.."      LuaJIT     : "..cfg.luajit_version.."\n"
    end
-   buf = buf.."      LUA        : "..show_status(cfg.variables.LUA, lua_ok).."\n"
+   buf = buf.."      LUA        : "..show_status(cfg.variables.LUA, lua_ok, "interpreter not found").."\n"
    if not lua_ok then
       buf = buf .. use_to_fix_location("variables.LUA", lua_example)
    end
-   buf = buf.."      LUA_INCDIR : "..show_status(cfg.variables.LUA_INCDIR, incdir_ok).."\n"
+   buf = buf.."      LUA_INCDIR : "..show_status(cfg.variables.LUA_INCDIR, incdir_ok, "lua.h not found").."\n"
    if lua_ok and not incdir_ok then
       buf = buf .. use_to_fix_location("variables.LUA_INCDIR")
    end
-   buf = buf.."      LUA_LIBDIR : "..show_status(cfg.variables.LUA_LIBDIR, libdir_ok).."\n"
+   buf = buf.."      LUA_LIBDIR : "..show_status(cfg.variables.LUA_LIBDIR, libdir_ok, "Lua library itself not found").."\n"
    if lua_ok and not libdir_ok then
       buf = buf .. use_to_fix_location("variables.LUA_LIBDIR")
    end
diff --git a/src/luarocks/cmd/config.lua b/src/luarocks/cmd/config.lua
index a01d33a9..26d60f09 100644
--- a/src/luarocks/cmd/config.lua
+++ b/src/luarocks/cmd/config.lua
@@ -243,11 +243,59 @@ local function get_scope(args)
           or "user"
 end
 
+local function report_on_lua_incdir_config(value, lua_version)
+   local variables = {
+      ["LUA_DIR"] = cfg.variables.LUA_DIR,
+      ["LUA_BINDIR"] = cfg.variables.LUA_BINDIR,
+      ["LUA_INCDIR"] = value,
+      ["LUA_LIBDIR"] = cfg.variables.LUA_LIBDIR,
+      ["LUA"] = cfg.variables.LUA,
+   }
+
+   local ok, err = deps.check_lua_incdir(variables, lua_version)
+   if not ok then
+      util.printerr()
+      util.warning((err:gsub(" You can use.*", "")))
+   end
+   return ok
+end
+
+local function report_on_lua_libdir_config(value, lua_version)
+   local variables = {
+      ["LUA_DIR"] = cfg.variables.LUA_DIR,
+      ["LUA_BINDIR"] = cfg.variables.LUA_BINDIR,
+      ["LUA_INCDIR"] = cfg.variables.LUA_INCDIR,
+      ["LUA_LIBDIR"] = value,
+      ["LUA"] = cfg.variables.LUA,
+   }
+
+   local ok, err, _, err_files = deps.check_lua_libdir(variables, lua_version)
+   if not ok then
+      util.printerr()
+      util.warning((err:gsub(" You can use.*", "")))
+      util.printerr("Tried:")
+      for _, l in pairs(err_files) do
+         for _, d in ipairs(l) do
+            util.printerr("\t" .. d)
+         end
+      end
+   end
+   return ok
+end
+
+local function warn_bad_c_config()
+   util.printerr()
+   util.printerr("LuaRocks may not work correctly when building C modules using this configuration.")
+   util.printerr()
+end
+
 --- Driver function for "config" command.
 -- @return boolean: True if succeeded, nil on errors.
 function config_cmd.command(args)
-   deps.check_lua_incdir(cfg.variables, args.lua_version or cfg.lua_version)
-   deps.check_lua_libdir(cfg.variables, args.lua_version or cfg.lua_version)
+   local lua_version = args.lua_version or cfg.lua_version
+
+   deps.check_lua_incdir(cfg.variables, lua_version)
+   deps.check_lua_libdir(cfg.variables, lua_version)
 
    -- deprecated flags
    if args.lua_incdir then
@@ -312,13 +360,43 @@ function config_cmd.command(args)
          local prefix = dir.dir_name(cfg.config_files[scope].file)
          persist.save_default_lua_version(prefix, args.lua_version)
       end
-      return write_entries(keys, scope, args.unset)
+      local ok, err = write_entries(keys, scope, args.unset)
+      if ok then
+         local inc_ok = report_on_lua_incdir_config(cfg.variables.LUA_INCDIR, lua_version)
+         local lib_ok = ok and report_on_lua_libdir_config(cfg.variables.LUA_LIBDIR, lua_version)
+         if not (inc_ok and lib_ok) then
+            warn_bad_c_config()
+         end
+      end
+
+      return ok, err
    end
 
    if args.key then
+      if args.key:match("^[A-Z]") then
+         args.key = "variables." .. args.key
+      end
+
       if args.value or args.unset then
          local scope = get_scope(args)
-         return write_entries({ [args.key] = args.value or args.unset }, scope, args.unset)
+
+         local ok, err = write_entries({ [args.key] = args.value or args.unset }, scope, args.unset)
+
+         if ok then
+            if args.key == "variables.LUA_INCDIR" then
+               local ok = report_on_lua_incdir_config(args.value, lua_version)
+               if not ok then
+                  warn_bad_c_config()
+               end
+            elseif args.key == "variables.LUA_LIBDIR" then
+               local ok = report_on_lua_libdir_config(args.value, lua_version)
+               if not ok then
+                  warn_bad_c_config()
+               end
+            end
+         end
+
+         return ok, err
       else
          return print_entry(args.key, cfg, args.json)
       end
diff --git a/src/luarocks/deps.lua b/src/luarocks/deps.lua
index 16631c58..1cd500ca 100644
--- a/src/luarocks/deps.lua
+++ b/src/luarocks/deps.lua
@@ -703,10 +703,10 @@ local function lua_h_exists(d, luaver)
       if data:match("LUA_VERSION_NUM%s*" .. tostring(luanum)) then
          return d
       end
-      return nil, "Lua header found at " .. d .. " does not match Lua version " .. luaver .. ". You may want to override this by configuring LUA_INCDIR.", "dependency", 2
+      return nil, "Lua header lua.h found at " .. d .. " does not match Lua version " .. luaver .. ". You can use `luarocks config variables.LUA_INCDIR <path>` to set the correct location.", "dependency", 2
    end
 
-   return nil, "Failed finding Lua header files (searched at " .. d .. "). You may need to install them or configure LUA_INCDIR.", "dependency", 1
+   return nil, "Failed finding Lua header lua.h (searched at " .. d .. "). You may need to install Lua development headers. You can use `luarocks config variables.LUA_INCDIR <path>` to set the correct location.", "dependency", 1
 end
 
 local function find_lua_incdir(prefix, luaver, luajitver)
@@ -793,7 +793,7 @@ function deps.check_lua_libdir(vars)
    end
    local cache = {}
    local save_LUA_INCDIR = vars.LUA_INCDIR
-   local ok = check_external_dependency("LUA", { library = libnames }, vars, "build", cache)
+   local ok, _, _, errfiles = check_external_dependency("LUA", { library = libnames }, vars, "build", cache)
    vars.LUA_INCDIR = save_LUA_INCDIR
    local err
    if ok then
@@ -806,7 +806,7 @@ function deps.check_lua_libdir(vars)
             ok = txt:match("Lua " .. cfg.lua_version, 1, true)
                  or txt:match("lua" .. (cfg.lua_version:gsub("%.", "")), 1, true)
             if not ok then
-               err = "Lua library at " .. filename .. " does not match Lua version " .. cfg.lua_version .. ". You may want to override this by configuring LUA_LIBDIR."
+               err = "Lua library at " .. filename .. " does not match Lua version " .. cfg.lua_version .. ". You can use `luarocks config variables.LUA_LIBDIR <path>` to set the correct location."
             end
          end
 
@@ -819,8 +819,8 @@ function deps.check_lua_libdir(vars)
       vars.LUA_LIBDIR_OK = true
       return true
    else
-      err = err or "Failed finding Lua library. You may need to configure LUA_LIBDIR."
-      return nil, err, "dependency"
+      err = err or "Failed finding the Lua library. You can use `luarocks config variables.LUA_LIBDIR <path>` to set the correct location."
+      return nil, err, "dependency", errfiles
    end
 end