/tmp/lazygit precludes use by multiple users

[tesujimath]

Describe the bug
When on a multi-user server, if anyone else is using lazygit they will own /tmp/lazygit, which prevents a second user from running it.

To Reproduce

$ lazygit
2025/08/05 16:26:27 mkdir /tmp/lazygit/2643863687: permission denied
login-1$ ls -ld /tmp/lazygit
drwx------. 3 zaphod zaphod 60 Aug  4 14:23 /tmp/lazygit

Expected behavior
I expected the second user to be able to run lazygit

Version info:

 lazygit --version
commit=, build date=, build source=nix, version=0.54.0, os=linux, arch=amd64, git version=2.39.3

Suggested fix
Use /tmp/lazygit-$USER instead of the existing path, so multiple users can harmlessly co-exist.

[stefanhaller]

This was of course caused by the last commit (3a9dbf7) of #4784, which creates the global lazygit temp dir with 700 permissions.

We have the following options for fixing it:

1. Revert that commit. Users will then see one lazygit-* temp dir for every instance of lazygit that is running, and those directories would leak when lazygit crashes or is force-killed. Apart from that, however, the problem of temp dir pollution should be fixed by the earlier commit of Improve temp dir handling #4784.
2. Add the user id to the global temp dir name, as determined by the Current() function of the os/user package. Might not be worth the effort.
3. Create the directory with 777 permissions instead. Could still cause failures if users have a more restricted umask, and also requires manual cleanup for affected users after they update to the new version.

I'd say 3. has too many downsides, but we could still decide between 1 and 2. I guess I have a slight tendency for 1 because it's easier, and probably good enough.

@waldauf Any opinions?

@tesujimath How would you assess the severity of this? Can releasing a fix wait until the next scheduled release (which happens on Sep 6), or should we release an 0.54.1 hotfix now?

[tesujimath]

I would say pretty urgent. I am supporting a couple of users with git stuff just now, and if this isn't fixed until September then they'll surely give up with lazygit and learn another git client. 😢

That is to say, it completely blocks their use of lazygit, alas.

[stefanhaller]

That's good input, I'll see what I can do.

That is to say, it completely blocks their use of lazygit, alas.

It's not that there's no workaround though: they just have to do sudo chmod 777 /tmp/lazygit, or am I missing something? If they don't have sudo access, they'll need to find the user who created the folder and ask them to do it, of course.

[stefanhaller]

Here's a PR: #4796

@tesujimath @waldauf Please test!

(In case it isn't obvious from the PR, I decided to go with option 2. after all; it wasn't too hard, and it gives a slightly better user experience for those who care about a clean /tmp dir. I was careful to handle any errors in such a way that we fall back to what we did before 0.54.0 in case anything goes wrong with the user id.)

[tesujimath]

Works for me, thanks for the quick response!