Re: [PATCH 2/2] stash: remove the stash.useBuiltin setting

> -	if (!use_builtin_stash()) {
> -		const char *path = mkpath("%s/git-legacy-stash",
> -					  git_exec_path());
> -
> -		if (sane_execvp(path, (char **)argv) < 0)
> -			die_errno(_("could not exec %s"), path);
> -		else
> -			BUG("sane_execvp() returned???");
> -	}
> -
>  	prefix = setup_git_directory();
>  	trace_repo_setup(prefix);
>  	setup_work_tree();
>  
>  	git_config(git_stash_config, NULL);
>  
> +	if (use_legacy_stash ||
> +	    !git_env_bool("GIT_TEST_STASH_USE_BUILTIN", -1))
> +		warning(_("the stash.useBuiltin support has been removed!\n"
> +			  "See its entry in 'git help config' for details."));