git prompt extremely slow on git repos with lots of commits.

[phryk]

Meta

Fish: 3.4.1
OS: FreeBSD 13.0
Terminal: rxvt-unicode

No third-party customizations.

Reproduction

Use one of the predefined prompts showing git info, like "Informative Vcs" or "Terlar".

git clone https://git.freebsd.org/ports.git
cd ports

Expected behavior

Change directory and give me access to my shell back, fast.

Actual behavior

Shell session blocked for ~15s.

Fix

Have __terlar_git_prompt and fish_git_prompt pass -uno to git status,
which makes it ignore untracked files. This speeds up the prompt generation
by a factor of something like 30-100, even when no untracked files are around.

fish_git_prompt has some settings that would make this invalid behavior
(show_informative_status, showuntrackedfiles), but -uno should at least
be the default because it makes the prompt on big repos so much faster.

I would also argue that a timeout like proposed by @cg505 and @krobelus
in #6764 should be wrapped around calls to prompt functions.

[IlanCosman]

Not that this solves the problem, since the default prompts should still be responsive, but you might want to check out https://github.com/IlanCosman/tide, which has an async git prompt. 0 delay ever, always have access to your shell. Sorry for the plug, just want to make sure you have a good fish experience 😅

[faho]

If -uno helps, your problem isn't lots of commits - it's lots of files.

And the normal fish_git_prompt already doesn't care about untracked files, it requires you to specifically set $__fish_git_prompt_showuntrackedfiles (and to not have git's bash.showuntrackedfiles option set to false on that repo).

What you're using however is the informative mode (which the informative sample prompt turns on). In this mode it's meant to count all the files. We pass "-unormal" (not "-uno") to not descend into untracked directories. If we passed -uno instead it wouldn't count untracked files at all, which doesn't seem right. (for historical reasons, the terlar prompt has its own git prompt implementation - I've been working on unifying the two)

The fish_git_prompt documentation already tells you that informative mode might be slow, and already explains you can disable it per-repo with:

git config --local bash.showInformativeStatus false

So really, what we could do, other than 6764, is to remove the informative prompt so at least you'd have to enable informative mode yourself. (we should also either remove or unify the terlar prompt because it does unnecessary work)