perf: reset packpath to only include the lazy package. Improved my startup time by 2ms

lua/lazy/core/config.lua

@@ -10,7 +10,6 @@ M.defaults = {
     version = nil,
     -- version = "*", -- enable this to try installing the latest stable versions of plugins
   },
-  packpath = vim.fn.stdpath("data") .. "/site/pack/lazy", -- package path where new plugins will be installed
   lockfile = vim.fn.stdpath("config") .. "/lazy-lock.json", -- lockfile generated after running update.
   install_missing = true, -- install missing plugins on startup. This doesn't increase startup time.
   concurrency = nil, -- set to a number to limit the maximum amount of concurrent tasks
@@ -20,6 +19,11 @@ M.defaults = {
     log = { "--since=1 days ago" }, -- commits from the last 3 days
     timeout = 120, -- processes taking over 2 minutes will be killed
   },
+  package = {
+    path = vim.fn.stdpath("data") .. "/site",
+    name = "lazy", -- plugins will be installed under package.path/pack/{name}/opt
+    reset = true, -- packpath will be reset to only include lazy. This makes packadd a lot faster
+  },
   -- Any plugin spec that contains one of the patterns will use your
   -- local repo in the projects folder instead of fetchig it from github
   -- Mostly useful for plugin developers.
@@ -49,6 +53,8 @@ M.defaults = {
 M.ns = vim.api.nvim_create_namespace("lazy")
 
 M.paths = {
+  ---@type string
+  opt = nil,
   ---@type string
   main = nil,
   ---@type string
@@ -69,6 +75,11 @@ function M.setup(opts)
   M.options = vim.tbl_deep_extend("force", M.defaults, opts or {})
   M.paths.plugins = vim.fn.stdpath("config") .. "/lua/" .. M.options.plugins:gsub("%.", "/")
   M.paths.main = M.paths.plugins .. (vim.loop.fs_stat(M.paths.plugins .. ".lua") and ".lua" or "/init.lua")
+  M.paths.opt = M.options.package.path .. "/pack/" .. M.options.package.name .. "/opt"
+
+  if M.options.package.reset then
+    vim.go.packpath = M.options.package.path
+  end
 
   vim.api.nvim_create_autocmd("User", {
     pattern = "VeryLazy",

lua/lazy/core/plugin.lua

@@ -147,7 +147,7 @@ end
 function M.update_state()
   ---@type table<string,FileType>
   local installed = {}
-  Util.ls(Config.options.packpath .. "/opt", function(_, name, type)
+  Util.ls(Config.paths.opt, function(_, name, type)
     if type == "directory" or type == "link" then
       installed[name] = type
     end
@@ -165,7 +165,7 @@ function M.update_state()
         or plugin.cmd
       plugin.lazy = lazy and true or false
     end
-    plugin.dir = Config.options.packpath .. "/opt/" .. plugin.name
+    plugin.dir = Config.paths.opt .. "/" .. plugin.name
     plugin._.is_local = plugin.uri:sub(1, 4) ~= "http" and plugin.uri:sub(1, 3) ~= "git"
     plugin._.is_symlink = installed[plugin.name] == "link"
     plugin._.installed = installed[plugin.name] ~= nil
@@ -178,7 +178,7 @@ function M.update_state()
   for pack, dir_type in pairs(installed) do
     table.insert(Config.to_clean, {
       name = pack,
-      dir = Config.options.packpath .. "/opt/" .. pack,
+      dir = Config.paths.opt .. "/" .. pack,
       _ = {
         installed = true,
         is_symlink = dir_type == "link",

lua/lazy/core/util.lua

@@ -40,8 +40,8 @@ function M.try(fn, msg)
       end
       if info.what == "Lua" and not info.source:find("lazy.nvim") then
         local source = info.source:sub(2)
-        if source:find(Config.options.packpath, 1, true) == 1 then
+        if source:find(Config.paths.opt, 1, true) == 1 then
-          source = source:sub(#Config.options.packpath + 1):gsub("^/opt/", ""):gsub("^/start/", "")
+          source = source:sub(#Config.paths.opt + 1)
         end
         source = vim.fn.fnamemodify(source, ":p:~:.")
         local line = "  - " .. source .. ":" .. info.currentline