Pin a patch with sha256sum

sha256sum makes sure a patch file is exactly the one you checked. If the file changes, apply refuses it.

Pin it

Get the hash:

sha256sum patches/requests/0001-fix.patch

625d70c05b1268bb99b5efbc82eaaf76ef615ecd20e3ace58048a608dad26f3e  patches/requests/0001-fix.patch

Add it to the entry:

version: 1
patches:
  - package: requests
    path: patches/requests/0001-fix.patch
    sha256sum: 625d70c05b1268bb99b5efbc82eaaf76ef615ecd20e3ace58048a608dad26f3e

When the file changes

error: sha256 mismatch for patches/requests/0001-fix.patch (expected 625d…, got 9a1f…)

The patch is not applied. The failure is recorded in the manifest.

Check what changed. If the change is fine, put the new hash into the patches file.

When to pin

  • Pin a patch that is done. It protects you from a patch file that was changed by mistake, or on purpose.

  • Do not pin yet while you still work on a patch. See Work on a patch.

[!TIP] Line endings change the hash. If git may change them on checkout, add *.patch -text to your .gitattributes.

Without a pin

venv-patcher still records the hash of each patch it applied. On the next apply it compares the file with that hash:

  • the same: the patch is skipped;

  • changed: apply stops and asks for --force.

So a changed patch is never applied on top of the old one.