Re: "add worktree" fails with "fatal: Invalid path" error

[Duy Nguyen <pclouds@gmail.com>]

On Sun, May 12, 2019 at 5:14 PM Shaheed Haque <shaheedhaque@gmail.com> wrote:
>
> Hi,
>
> I'm running git v.2.20.1 on Ubuntu from a program which follows the pattern:
>
> ============
> 1. create a temporary directory /tmp/tmpabc

When is this directory deleted? After step 3a?

> 2. in a loop:
>     2a. create a second level of temporary directory /tmp/tmpabc/tmpworktree123
>     2b. use "git worktree add" on the second level directory
>     2c. do something
> 3. cleanup
>     3b. "git branch -D" on each basename(second level directory)
>     3a. "git worktree prune"
> ============
>
> The loop size is of the order of 8-20. In step 2b, I often get errors
> like this (from a Bash reproducer):
>
> ============
> $ git worktree add /tmp/tmpgtxug4y9/git_worktree.gBGqnfnU
> Preparing worktree (new branch 'git_worktree.gBGqnfnU')
> fatal: Invalid path '/tmp/tmp1q9ysvyl': No such file or directory
> ============
>
> I can see that the problematic path exists in the "gitdir" file of
> what must be an earlier worktree from an older run (the branch is
> gone, but the tree is still there). The path appear to relate to the
> older run's first level directory:
>
> ============
> $ grep -r /tmp/tmp1q9ysvyl ../.git/worktrees/
> ../.git/worktrees/git_worktree.frcwtjt_/gitdir:/tmp/tmp1q9ysvyl/git_worktree.frcwtjt_/.git
> $ git worktree list
> ...
> /tmp/tmp1q9ysvyl/git_worktree.frcwtjt_  edde3f25 (detached HEAD)
> ...
> $ git branch | grep frcwtjt_
> <no matches>
> ============

Yeah I think I know where that "Invalid path" comes from and it should
not be there (at least it should not be a fatal error). I'll need to
reproduce this first. But I'm certain you've given me enough
information to do so.

> NOTE: I've not yet had to try deleting the worktree, since "add
> worktree" does appear to work some of the time, so I am able to limp
> along.

It's probably best to stay clean and delete things after you're done.
At least you should be able to avoid this problem this way until it's
fixed.

>
> I have these questions:
>
> 1. There is no branch or first level directory, but "git prune" has
> not deleted the worktree, is this expected?

I assume you meant "git worktree prune", not "git prune". See
gc.worktreePruneExpire. Dead worktree info stays for a while until
it's deleted, so that you can recover stuff if you need to.

> 2. Is there something wrong with the sequence of steps I am following?

Nope. I mean, you could try "git worktree remove" to be on the safe
side. But it should work even without that. To me this looks very much
like a bug.

> Thanks, Shaheed
>
> P.S. I have an strace of a failing worktree add if needed.
-- 
Duy