From: Jörg Thalheim Date: Mon, 11 May 2026 09:06:00 GMT Subject: Re: [PATCH] config: retry acquiring config.lock for 100ms Message-ID: <91335804a092b09757331cac72092a3835020b3a@thalheim.io> In-Reply-To: I am not really sure what you want me to do here. I don't see how git can have this value configurable, given it's about reading the configuration itself. Is the user supposed via command line? Meanwhile the project I was facing this issue, added the required file lock in its own code, which has since then worked perfectly to fix my use case: https://github.com/raine/workmux/issues/116 May 11, 2026 at 4:32 AM, "Junio C Hamano" wrote: > > Patrick Steinhardt writes: > > > > > > > > > This bites in practice when running `git worktree add -b` concurrently > > > against the same repository. Each invocation makes several writes to > > > ".git/config" to set up branch tracking, and tooling that creates > > > worktrees in parallel sees intermittent failures. Worse, `git worktree > > > add` does not propagate the failed config write to its exit code: the > > > worktree is created and the command exits 0, but tracking > > > configuration is silently dropped. > > > > > This very much sounds like a bug that is worth fixing independently. > > > > > > > > The lock is held only for the duration of rewriting a small file, so > > > retrying for 100 ms papers over any realistic contention while still > > > failing fast if a stale lock has been left behind by a crashed > > > process. This mirrors what we already do for individual reference > > > locks (4ff0f01cb7 (refs: retry acquiring reference locks for 100ms, > > > 2017-08-21)). > > > > > Famous last words :) Experience tells me that any timeout value that > > isn't excessive will eventually be hit in some production system. Which > > raises the question whether we want to make the timeout configurable, > > similar to "core.filesRefLockTimeout" and "core.packedRefsTimeout". > > ... > > Honestly though, I'm not really sure what to make with this. We could > > of course also add some validation that the configuration we want to set > > hasn't been modified meanwhile. But that would now lead to a situation > > where we have to update every single caller in our tree to make use of > > the new mechanism, which would be a bunch of work. > > > > And adding the timeout doesn't really change the status quo, either. We > > already have the case that we'll happily overwrite changes made by > > concurrent processes. The only thing that changes is that we make it > > more likely for concurrent changes to succeed. > > > We haven't heard any response to these points raised in the message > I am responding to. Should I still keep the patch in my tree, > hoping that a responses may come some day? I am tempted to discard > the topic as it has been quite a while since we last looked at it. > > Thanks. >