chore(git): consistent error reporting on git failures

lua/git/repo.lua

@@ -1,3 +1,4 @@
+local log = require("log")
 local util = require("util")
 
 local UNMERGED = {
@@ -73,6 +74,7 @@ local function resolve(path)
     f:close()
     local gitdir = content:match("gitdir:%s*(%S+)")
     if not gitdir then
+        log.warning(".git file at %s has no `gitdir:` line", found)
         return nil
     end
     if not gitdir:match("^/") then
@@ -148,6 +150,8 @@ local function do_refresh(repo)
                     statuses[vim.fs.joinpath(repo.worktree, path_part)] =
                         format(code)
                 end
+            else
+                log.warning("git status failed: %s", vim.trim(obj.stderr or ""))
             end
             local dirty = false
             for buf in pairs(repo.buffers) do