[Groxx]

gitignores are usually committed (they're treated like a normal file), so yes, in this context that would delete it from everyone.

There's .git/info/exclude, but that has some kinda large surprises if it excludes a tracked file and I don't recommend anyone use it unless they know what to look for and can always remember what they've excluded.

[sanderjd]

I have a $HOME/.gitignore that I use for this. (You can configure git to use that globally.) It's not a panacea, and I think other commenters are right that you should instead endeavor to organize things so that the project's own gitignore results in a sane workflow. But I think having permanently unstaged changes is worse.

[happymellon]

It's the perfect location to ignore *.log.

Git will fight you if you ignore .config files which are actually used.