feat(loader): warn when mapleader is changed after init

lua/lazy/core/config.lua

@@ -111,6 +111,9 @@ M.options = {}
 ---@type string
 M.me = nil
 
+---@type string
+M.mapleader = nil
+
 ---@param spec LazySpec
 ---@param opts? LazyConfig
 function M.setup(spec, opts)
@@ -143,6 +146,7 @@ function M.setup(spec, opts)
 
   -- disable plugin loading since we do all of that ourselves
   vim.go.loadplugins = false
+  M.mapleader = vim.g.mapleader
 
   vim.api.nvim_create_autocmd("User", {
     pattern = "VeryLazy",

lua/lazy/manage/reloader.lua

@@ -2,6 +2,7 @@ local Cache = require("lazy.core.cache")
 local Config = require("lazy.core.config")
 local Util = require("lazy.util")
 local Plugin = require("lazy.core.plugin")
+local Loader = require("lazy.core.loader")
 
 local M = {}
 
@@ -63,6 +64,11 @@ function M.check(start)
     end
   end
 
+  if Loader.init_done and Config.mapleader ~= vim.g.mapleader then
+    require("lazy.core.util").warn("You need to set `vim.g.mapleader` **BEFORE** loading lazy")
+    Config.mapleader = vim.g.mapleader
+  end
+
   if not (start or #changes == 0) then
     vim.schedule(function()
       if Config.options.change_detection.notify then