Re: [Feature request] Support b4 prerequisite-patch-id dependencies when applying patchsets

[Roman Gushchin <roman.gushchin@linux.dev>]

robin@snyders.xyz writes:

> Hi,
>
> I ran into a Failed To Apply result in Sashiko for a kernel patch series that uses b4 prerequisite dependencies.
>
> Affected Sashiko patchset:
> https://sashiko.dev/#/patchset/20260812-submit-qcom-smbx-send-v1-v2-0-f504b8f9bfad%40snyders.xyz
>
> Lore thread:
> https://lore.kernel.org/r/20260812-submit-qcom-smbx-send-v1-v2-0-f504b8f9bfad@snyders.xyz/
>
> The series is based on:
>
> base-commit: 99b38cda3f4c486cfbc40f3c8ede1703594e9f13
>
> and declares five prerequisite patches using b4 dependency metadata:
>
> prerequisite-patch-id: 3d8a9cf43b5e5eac64a60aeec5e9c90880bcf792
> prerequisite-patch-id: de3e3b494f9644596cfa4cafc362ca0b48288c45
> prerequisite-patch-id: d5e22a0fe7cd55374f60d7c2cb14ed3df8f94e0b
> prerequisite-patch-id: 9eafa41402e97d6a3e5369bec46df4e9db3d2af6
> prerequisite-patch-id: 5638b901cd10773fa9485605f84b25a1dd826a84
>
> Those five prerequisites are the preceding qcom_smbx fixes series:
> https://lore.kernel.org/r/20260812-qcom-smbx-fixes-v1-0-eb48246be599@snyders.xyz/
>
> The SMB5 v2 series intentionally depends on that fixes series because
> both modify overlapping areas of
> drivers/power/supply/qcom_smbx.c. Applying the v2 directly to the base
> tree without first applying the declared prerequisites is therefore
> expected to fail.
>
> On the Sashiko page, the result is Failed To Apply, Baseline shows
> Selected: -, and no AI review is run. From looking at the current
> baseline/application logic, it appears Sashiko applies the patches in
> the current patchset to a candidate baseline but does not resolve and
> apply b4 prerequisite-patch-id dependencies first.
>
> Expected behaviour would be roughly:
>
> Resolve the base commit.
> Resolve each prerequisite-patch-id from public-inbox/Lore.
> Apply the prerequisite patches in dependency order.
> Apply the patchset being reviewed.
> Run the normal review on the resulting tree.
>
> b4 itself supports this dependency metadata, and b4 prep --check-deps can validate that the dependency chain is available and applicable.
>
> If automatically resolving prerequisite-patch-id is intentionally out
> of scope, it would still be useful for Failed To Apply to report that
> unresolved prerequisite metadata was present, rather than making the
> failure look like the submitted series itself does not apply.
>
> Please let me know if you would like any additional reproduction
> details or the exact b4 commands used to prepare the series.

b4 support is in progress:
https://github.com/sashiko-dev/sashiko/pull/389

Thanks