Welcome to GitGitGadget

Hi @adacosta, and welcome to GitGitGadget, the GitHub App to send patch series to the Git mailing list from GitHub Pull Requests.

Please make sure that either:

• Your Pull Request has a good description, if it consists of multiple commits, as it will be used as cover letter.
• Your Pull Request description is empty, if it consists of a single commit, as the commit message should be descriptive enough by itself.

You can CC potential reviewers by adding a footer to the PR description with the following syntax:

CC: Revi Ewer <revi.ewer@example.com>, Ill Takalook <ill.takalook@example.net>

NOTE: DO NOT copy/paste your CC list from a previous GGG PR's description,
because it will result in a malformed CC list on the mailing list. See
example.

Also, it is a good idea to review the commit messages one last time, as the Git project expects them in a quite specific form:

• the lines should not exceed 76 columns,
• the first line should be like a header and typically start with a prefix like "tests:" or "revisions:" to state which subsystem the change is about, and
• the commit messages' body should be describing the "why?" of the change.
• Finally, the commit messages should end in a Signed-off-by: line matching the commits' author.

It is in general a good idea to await the automated test ("Checks") in this Pull Request before contributing the patches, e.g. to avoid trivial issues such as unportable code.

Contributing the patches

Before you can contribute the patches, your GitHub username needs to be added to the list of permitted users. Any already-permitted user can do that, by adding a comment to your PR of the form /allow. A good way to find other contributors is to locate recent pull requests where someone has been /allowed:

• Search: is:pr is:open "/allow"

Both the person who commented /allow and the PR author are able to /allow you.

An alternative is the channel #git-devel on the Libera Chat IRC network:

<newcontributor> I've just created my first PR, could someone please /allow me? https://github.com/gitgitgadget/git/pull/12345
<veteran> newcontributor: it is done
<newcontributor> thanks!

Once on the list of permitted usernames, you can contribute the patches to the Git mailing list by adding a PR comment /submit.

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After you submit, GitGitGadget will respond with another comment that contains the link to the cover letter mail in the Git mailing list archive. Please make sure to monitor the discussion in that thread and to address comments and suggestions (while the comments and suggestions will be mirrored into the PR by GitGitGadget, you will still want to reply via mail).

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To iterate on your change, i.e. send a revised patch or patch series, you will first want to (force-)push to the same branch. You probably also want to modify your Pull Request description (or title). It is a good idea to summarize the revision by adding something like this to the cover letter (read: by editing the first comment on the PR, i.e. the PR description):

Changes since v1:
- Fixed a typo in the commit message (found by ...)
- Added a code comment to ... as suggested by ...
...

To send a new iteration, just add another PR comment with the contents: /submit.

Need help?

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There are issues in commit 1f3461a:
lockfile: add case insensitive filesystem note
Commit checks stopped - the message is too short
Commit not signed off

There are issues in commit c59187c:
lockfile: add case insensitive filesystem note
Commit checks stopped - the message is too short
Commit not signed off

There are issues in commit 0005140:
lockfile: add case insensitive filesystem note
Commit checks stopped - the message is too short
Commit not signed off

There are issues in commit e7e4b0e:
doc: add case insensitive filesystem note
Commit checks stopped - the message is too short
Commit not signed off

There are issues in commit 40a07f1:
doc: add case insensitive filesystem note
Commit not signed off

There are issues in commit 6b39e64:
doc: add case insensitive filesystem note
Commit not signed off

There are issues in commit 0ab95ab:
lockfile: add case insensitive filesystem note
Commit not signed off

/allow

User adacosta is now allowed to use GitGitGadget.

@adacosta the Git project is very particular with commit messages. You will want to review the guidance in https://github.blog/2022-06-30-write-better-commits-build-better-projects/ to improve your commit message (git commit --amend), in particular with a strong focus on this part:

Also, could you please sign off on your patch? The Git project insists on that. You can fix it by git commit --amend --signoff, and force-pushing.

I am sorry for all the red tape...

I think this PR will be helpful to developers facing this issue, as it eliminates the time it takes to understand the issue and fix it within one's repository or filesystem.

@dscho thanks for the feedback! Not included in my patch are the translations because I'm not sure how they're handled. Does my PR need to be flagged to translate? For an example of files, search "Another git process seems to be running in this repository".

Not included in my patch are the translations because I'm not sure how they're handled. Does my PR need to be flagged to translate?

The message you modify is enclosed in _(...). That marks it for translation, and the excellent translators over at https://github.com/git-l10n/git-po typically do a very good job at adjusting the translations during the "-rc phase" short before the next .0 version comes out.

@adacosta did you mean to /submit this?

/submit

Submitted as pull.2053.git.git.1758578084468.gitgitgadget@gmail.com

To fetch this version into FETCH_HEAD:

git fetch https://github.com/gitgitgadget/git/ pr-git-2053/adacosta/lockfile-add-case-insensitive-filesystem-note-v1

To fetch this version to local tag pr-git-2053/adacosta/lockfile-add-case-insensitive-filesystem-note-v1:

git fetch --no-tags https://github.com/gitgitgadget/git/ tag pr-git-2053/adacosta/lockfile-add-case-insensitive-filesystem-note-v1

On the Git mailing list, Junio C Hamano wrote (reply to this):

"Alan Da Costa via GitGitGadget" <gitgitgadget@gmail.com> writes:

> From: Alan Da Costa <alandacosta@gmail.com>
>
> * Add note of case insensitive client filesystems may error due to a lock
>   on a case variant ref to more quickly identify failure in fetch/pull

This does not have to be a single-item bulletted list.  Please lose
the leading "* " from the first line, and " " from the second line,
and finish the whole sentence with a full-stop "."

> Signed-off-by: Alan Da Costa <alandacosta@gmail.com>
> ---
>
>     When running git fetch or git pull on a case insensitive filesystem
>     (e.g., default macOS), if multiple case variants of the same remote ref
>     exist (often after a case-only rename), both variant locks map to the
>     same on-disk path. When a local update is required, Git creates a lock
>     for the first variant and then attempts to lock the second, which
>     collides with the same lock file, so an “existing lock” error is
>     reported.

And the message update may help unconfusing the user who gets this
error, which is a good idea.  Thanks for working on this.

>     The underlying issue is mixed-case refs; resolve it by
>     consolidating the remote to a single-case variant and update local refs
>     accordingly.

This does not seem to match anything the patch does, though ;-)

>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2053%2Fadacosta%2Flockfile-add-case-insensitive-filesystem-note-v1
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2053/adacosta/lockfile-add-case-insensitive-filesystem-note-v1
> Pull-Request: https://github.com/git/git/pull/2053
>
>  lockfile.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)

> diff --git a/lockfile.c b/lockfile.c
> index 1d5ed01682..99a470bd3d 100644
> --- a/lockfile.c
> +++ b/lockfile.c
> @@ -156,7 +156,10 @@ void unable_to_lock_message(const char *path, int err, struct strbuf *buf)
>  		    "an editor opened by 'git commit'. Please make sure all processes\n"
>  		    "are terminated then try again. If it still fails, a git process\n"
>  		    "may have crashed in this repository earlier:\n"
> -		    "remove the file manually to continue."),
> +		    "remove the file manually to continue.\n\n"
> +		    "On case insensitive client filesystems, multiple mixed-case refs will resolve\n"
> +		    "to the same lock file, possibly causing this error. If so, ensure your remote\n"
> +		    "refs have a single case variant."),
>  			    absolute_path(path), strerror(err));

The two lines in the new part of the message seem to be longer than
usual by two words or so.  Can you line wrap to balance?

The error is about our "local" filesystem, isn't it?  If you do not
have control over what the remote does, you have no recourse.  If
using the reftable backend on the local end work around the local
filesystem's case insensitivity, that would be a better suggestion
to give that such a user can actually act on.

In any case, wouldn't it make more sense to do this change
conditionally by looking at the value of the ignore_case global
(which in turn came from the core.ignorecase setting in .git/config
when the repository was created by probing the filesystem
capabilities)?  If you get this error and you are on a case
sensitive system, the additional hints will lead the user to a
wild goose chase.

Thanks.

There are issues in commit e18054e:
lockfile: add case insensitive filesystem note
Lines in the body of the commit messages should be wrapped between 60 and 76 characters.
Indented lines, and lines without whitespace, are exempt

On the Git mailing list, Patrick Steinhardt wrote (reply to this):

On Mon, Sep 22, 2025 at 09:54:44PM +0000, Alan Da Costa via GitGitGadget wrote:
> From: Alan Da Costa <alandacosta@gmail.com>
> When running git fetch or git pull on a case insensitive filesystem
> (e.g., default macOS), if multiple case variants of the same remote ref
> exist (often after a case-only rename), both variant locks map to the
> same on-disk path. When a local update is required, Git creates a lock
> for the first variant and then attempts to lock the second, which
> collides with the same lock file, so an “existing lock” error is
> reported. The underlying issue is mixed-case refs; resolve it by
> consolidating the remote to a single-case variant and update local refs
> accordingly.

Are you aware of Karthik's recent patch series at [1]? It looks like
this addresses your exact problem in a more direct way, and the
resulting error messages that we have in that patch series also give a
bit more advice for how to handle the situation.

The patch series wasn't merged yet, but will probably be merged soon.
Could you maybe test that series and say whether it addresses your need?

Thanks!

Patrick

[1]: https://lore.kernel.org/git/20250902-587-git-fetch-1-fails-fetches-on-case-insensitive-repositories-v1-0-35e69bbb507d@gmail.com/

User Patrick Steinhardt <ps@pks.im> has been added to the cc: list.

On the Git mailing list, Karthik Nayak wrote (reply to this):

Patrick Steinhardt <ps@pks.im> writes:

> On Mon, Sep 22, 2025 at 09:54:44PM +0000, Alan Da Costa via GitGitGadget wrote:
>> From: Alan Da Costa <alandacosta@gmail.com>
>> When running git fetch or git pull on a case insensitive filesystem
>> (e.g., default macOS), if multiple case variants of the same remote ref
>> exist (often after a case-only rename), both variant locks map to the
>> same on-disk path. When a local update is required, Git creates a lock
>> for the first variant and then attempts to lock the second, which
>> collides with the same lock file, so an “existing lock” error is
>> reported. The underlying issue is mixed-case refs; resolve it by
>> consolidating the remote to a single-case variant and update local refs
>> accordingly.
>
> Are you aware of Karthik's recent patch series at [1]? It looks like
> this addresses your exact problem in a more direct way, and the
> resulting error messages that we have in that patch series also give a
> bit more advice for how to handle the situation.
>

Thanks for tagging me.

>
> The patch series wasn't merged yet, but will probably be merged soon.
> Could you maybe test that series and say whether it addresses your need?
>

I agree. This should ideally be fixed with my series. Do let us know if
you test it. My series also has the added advantage that it would
suggest using reftables, wherein, the user can still use
case-conflicting refs in their repository.

> Thanks!
>
> Patrick
>
> [1]: https://lore.kernel.org/git/20250902-587-git-fetch-1-fails-fetches-on-case-insensitive-repositories-v1-0-35e69bbb507d@gmail.com/

User Karthik Nayak <karthik.188@gmail.com> has been added to the cc: list.