4 files changed, 65 insertions, 12 deletions

diff --git a/src/luarocks/cmd.lua b/src/luarocks/cmd.lua
index be863cfa..37266b40 100644
--- a/src/luarocks/cmd.lua
+++ b/src/luarocks/cmd.lua
@@ -266,7 +266,10 @@ do
          if args.lua_dir then
             local detected, err = util.find_lua(args.lua_dir, lua_version)
             if not detected then
-               die(err)
+               local suggestion = (not args.lua_version)
+                  and "\nYou may want to specify a different Lua version with --lua-version\n"
+                  or  ""
+               die(err .. suggestion)
             end
             return detected
          end
@@ -324,11 +327,45 @@ local function get_status(status)
    return status and "ok" or "not found"
 end
 
+local function use_to_fix_location(key)
+   local buf =  "                   ****************************************\n"
+   buf = buf .. "                   Use the command\n\n"
+   buf = buf .. "                      luarocks config " .. key .. " <dir>\n\n"
+   buf = buf .. "                   to fix the location\n"
+   buf = buf .. "                   ****************************************\n"
+   return buf
+end
+
 local function get_config_text(cfg)
-   local buf = "Configuration:\n   Lua version: "..cfg.lua_version.."\n"
+   local deps = require("luarocks.deps")
+
+   local libdir_ok = deps.check_lua_libdir(cfg.variables)
+   local incdir_ok = deps.check_lua_incdir(cfg.variables)
+   local bindir_ok = fs.exists(cfg.variables.LUA_BINDIR)
+   local luadir_ok = fs.exists(cfg.variables.LUA_DIR)
+   local lua_ok = fs.exists(cfg.variables.LUA)
+
+   local buf = "Configuration:\n"
+   buf = buf.."   Lua:\n"
+   buf = buf.."      Version    : "..cfg.lua_version.."\n"
    if cfg.luajit_version then
-      buf = buf.."   LuaJIT version: "..cfg.luajit_version.."\n"
+      buf = buf.."      LuaJIT     : "..cfg.luajit_version.."\n"
    end
+   buf = buf.."      Interpreter: "..(cfg.variables.LUA or "").." ("..get_status(lua_ok)..")\n"
+   buf = buf.."      LUA_DIR    : "..(cfg.variables.LUA_DIR or "").." ("..get_status(luadir_ok)..")\n"
+   if not lua_ok then
+      buf = buf .. use_to_fix_location("lua_dir")
+   end
+   buf = buf.."      LUA_BINDIR : "..(cfg.variables.LUA_BINDIR or "").." ("..get_status(bindir_ok)..")\n"
+   buf = buf.."      LUA_INCDIR : "..(cfg.variables.LUA_INCDIR or "").." ("..get_status(incdir_ok)..")\n"
+   if lua_ok and not incdir_ok then
+      buf = buf .. use_to_fix_location("variables.LUA_INCDIR")
+   end
+   buf = buf.."      LUA_LIBDIR : "..(cfg.variables.LUA_LIBDIR or "").." ("..get_status(libdir_ok)..")\n"
+   if lua_ok and not libdir_ok then
+      buf = buf .. use_to_fix_location("variables.LUA_LIBDIR")
+   end
+
    buf = buf.."\n   Configuration files:\n"
    local conf = cfg.config_files
    buf = buf.."      System  : "..fs.absolute_name(conf.system.file).." ("..get_status(conf.system.found)..")\n"
diff --git a/src/luarocks/cmd/config.lua b/src/luarocks/cmd/config.lua
index bdabe960..5e92634a 100644
--- a/src/luarocks/cmd/config.lua
+++ b/src/luarocks/cmd/config.lua
@@ -297,6 +297,10 @@ function config_cmd.command(args)
          ["variables.LUA_LIBDIR"] = cfg.variables.LUA_LIBDIR,
          ["lua_interpreter"] = cfg.lua_interpreter,
       }
+      if args.lua_version then
+         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)
    end
 
diff --git a/src/luarocks/core/cfg.lua b/src/luarocks/core/cfg.lua
index 0c79fc63..3917e2af 100644
--- a/src/luarocks/core/cfg.lua
+++ b/src/luarocks/core/cfg.lua
@@ -690,6 +690,8 @@ function cfg.init(detected, warning)
    if detected.given_lua_dir then
       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
       cfg.lua_interpreter = detected.lua_interpreter
    end
 
diff --git a/src/luarocks/deps.lua b/src/luarocks/deps.lua
index 0eb80193..d935a5c8 100644
--- a/src/luarocks/deps.lua
+++ b/src/luarocks/deps.lua
@@ -649,6 +649,16 @@ function deps.scan_deps(results, manifest, name, version, deps_mode)
    end
 end
 
+local function lua_h_exists(d)
+   local lua_h = dir.path(d, "lua.h")
+   local fd = io.open(lua_h)
+   if fd then
+      -- TODO check that LUA_VERSION_MAJOR and LUA_VERSION_MINOR match luaver
+      fd:close()
+      return d
+   end
+end
+
 local function find_lua_incdir(prefix, luaver, luajitver)
    luajitver = luajitver and luajitver:gsub("%-.*", "")
    local shortv = luaver:gsub("%.", "")
@@ -662,11 +672,7 @@ local function find_lua_incdir(prefix, luaver, luajitver)
       luajitver and prefix .. "/include/luajit-" .. luajitver:match("^(%d+%.%d+)"),
    }
    for _, d in ipairs(incdirs) do
-      local lua_h = dir.path(d, "lua.h")
-      local fd = io.open(lua_h)
-      if fd then
-         -- TODO check that LUA_VERSION_MAJOR and LUA_VERSION_MINOR match luaver
-         fd:close()
+      if lua_h_exists(d) then
          return d
       end
    end
@@ -678,14 +684,18 @@ end
 function deps.check_lua_incdir(vars)
    local ljv = util.get_luajit_version()
 
-   if (not vars.LUA_INCDIR) and vars.LUA_DIR then
+   if vars.LUA_INCDIR then
+      return lua_h_exists(vars.LUA_INCDIR)
+   end
+   
+   if vars.LUA_DIR then
       vars.LUA_INCDIR = find_lua_incdir(vars.LUA_DIR, cfg.lua_version, ljv)
-      if vars.LUA_INCDIR == nil then
-         return nil, "Failed finding Lua header files. You may need to install them or configure LUA_INCDIR.", "dependency"
+      if vars.LUA_INCDIR then
+         return true
       end
    end
 
-   return true
+   return nil, "Failed finding Lua header files. You may need to install them or configure LUA_INCDIR.", "dependency"
 end
 
 function deps.check_lua_libdir(vars)