LineageOS 23.2 on Pixel 7a (lynx): bootloop both after recovery install and after patching boot.img in APatch app

[JokerGermany]

This issue is written with the help of KI.

Checklist

• I searched existing issues and did not find the same problem.
• My report is written in English.
• I am attaching relevant logs.

Device info

• Device: Google Pixel 7a (lynx)
• ROM: LineageOS 23.2
• Build: 23.2-20260320-NIGHTLY-lynx
• Android version: 16
• APatch install methods tested:
  1. Recovery / adb sideload (APatch APK)
  2. Patching boot.img inside the APatch app and then flashing the patched image

Describe the bug

I get a bootloop with both installation methods on my Pixel 7a running LineageOS 23.2.

Method 1: When I install APatch from recovery via adb sideload, the installer starts normally and appears to patch the kernel in boot.img, but the installation process shows errors during script execution and file handling. After using the patched result, the device bootloops.

Method 2: I also tested creating a patched boot.img directly in the APatch app and then flashing that patched boot image manually. This also results in a bootloop.

Because both methods lead to the same result, this may not be limited to the recovery installer alone.

Steps to reproduce

1. Boot Pixel 7a (lynx) into recovery.
2. Start adb sideload mode.
3. Sideload the APatch package (APK renamed to ZIP).
4. Recovery verifies/extracts the package, parses boot.img, and starts patching.
5. During the install, the script reports:
   • sh: patch: unknown operand
   • mv: can't create data/boot.img: Permission denied
6. Boot the device -> bootloop.

Also reproducible with:

1. Extract the matching boot.img from the current ROM.
2. Patch boot.img in the APatch app.
3. Flash the patched boot image.
4. Reboot -> bootloop.

Expected behavior

APatch should patch the correct boot image and complete successfully without script or file permission errors, and the device should boot normally.

Relevant recovery log excerpts

• inflating lib/arm64-v8a/libapjni.so
• inflating assets/InstallAP.sh
• inflating assets/bootpatch.sh
• Parsing boot image boot.img
• patch done .kernel
• sh: patch: unknown operand
• mv: can't create data/boot.img: Permission denied

Additional info

• Recovery log shows LineageOS 23.2-20260320-NIGHTLY-lynx.
• Device is Pixel 7a / lynx.
• Device is A/B and recovery log lists both boot and initboot partitions.
• Recovery log indicates the APatch payload is extracted and kernel patching is attempted.
• The same bootloop also happens when using a boot.img patched in the APatch app and then flashing it manually.

Notes

I removed sensitive values like the superkey before posting.

recovery.log