fix(addon-loader): use Lua version from share/lua/5.X to require loader modules

Author: goldenstein64

src/luarocks/lls-addon-loader.lua

@@ -5,23 +5,38 @@ local fs = require("bee.filesystem")
 local furi = require("file-uri")
 local workspace = require("workspace")
 
-local start, _, dir_sep = string.find(package.path, "([/\\])luarocks%1%?%.lua$")
+-- this relies on the plugin module's behavior with modifying
+-- package.path... very fragile
+local luarocksLuaVersion, start = string.match(package.path, "(%d%.%d)()([/\\])luarocks%3%?%.lua$")
 assert(start, "could not replace path")
-package.path = string.sub(package.path, 1, start - 1) .. dir_sep .. "?.lua"
+package.path = string.sub(package.path, 1, start) .. "?.lua"
 
 local cfg = require("luarocks.core.cfg") --[[@as luarocks.core.cfg]]
-require("luarocks.loader")
 
 local workspaceRoot = fs.path(furi.decode(workspace.rootUri))
 local lua_modules = workspaceRoot / "lua_modules"
 if fs.exists(lua_modules:string()) then
 	print("luarocks-build-lls-addon: configured workspace as project directory")
 	-- re-initialize cfg with the project directory (loads in the project config from ./.luarocks)
-	cfg.init({ project_dir = workspaceRoot:string() })
+	assert(cfg.init({ project_dir = workspaceRoot:string(), lua_version = luarocksLuaVersion }))
+	cfg.init_package_paths()
 	-- add ./lua_modules as one of the queryable rocks trees
 	table.insert(cfg.rocks_trees, 1, { name = "project", root = lua_modules:string() } --[[@as luarocks.core.Tree]])
 end
 
+-- Stub out cfg.init() when `luarocks.loader` is running, since it calls the
+-- function unconditionally with no arguments.
+local oldInit = cfg.init
+function cfg.init()
+	return true
+end
+require("luarocks.loader")
+cfg.init = oldInit
+
+-- initialize it again with 5.5 so other plugins can use it
+cfg.init()
+cfg.init_package_paths()
+
 -- because of how `plugin.dispatch` works, leaving these functions undefined
 -- means plugins defined later can't use these callbacks!
 -- all thanks to this line: https://github.com/LuaLS/lua-language-server/blob/0187ddf19f940d8b9b95d916d73f4660ec417471/script/plugin.lua#L35