Re: [PATCH v3 4/6] diff: add long-running diff process via diff.<driver>.process

> On Sun, Jun 7, 2026 at 7:36 AM Johannes Schindelin
> <Johannes.Schindelin@gmx.de> wrote:
>>
>> Hi Michael,
>>
>> I stumbled about this patch when it broke CI in Git for Windows, where we
>> do _not_ use `NO_PYTHON`, even though Python is unavailable in the
>> build/test CI jobs. The existing tests handle this situation gracefully,
>> this here patch does not:
>> ...
>> Given the complexity of what t4080 tries to test (error, abort, crash,
>> bad-sync, no-hunks, multiple files in one session, capability
>> negotiation), it would unfortunately be infeasible to use `test-tool
>> pkt-line` from a shell script implementing that `diff.*.process` protocol.
>>
>> So I've spiked a demo how the `test-tool diff-process-backend` could look
>> like (letting Opus do the menial typing, so that I can enjoy at least part
>> of a sunny Sunday outside), which also passes the CI build and test:
>> https://github.com/dscho/git/commit/b6e3c93381b00929476c3a00155f7cf7334a22e6
>>
>> That commit is of course not intended to be used as-is; Feel free to pick
>> code parts of it and integrate them into your topic branch. Or write your
>> own test-tool helper from scratch if that's more your jam.
>>
>
> Johannes, thank you for the great feedback. The historical context is
> really helpful and
> the concerns you raise make a lot of sense. I will take a look at your
> spike and also work
> on removing Python from the test.