Question Troubleshooting re-locking bootloader on Pixel 6 Pro with a self-signed build of AOSP - Google Pixel 6

Trying to re-lock a Pixel 6 Pro using the vanilla AOSP, while some progress has been made since I last posted (link) it still isn't working. I'm at the point to where it "should" let me lock it and instead I'm getting this error message:
fastboot flashing lock
FAILED (remote: 'invalid android images, skip locking')
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Other than that, it boots just fine. My best guess is that something went wrong when signing. I'm following instructions from here for signing the build with some customization below. Here's a summary of the entire process.
Checkout the source code:
repo init -u https://android.googlesource.com/platform/manifest -b android-13.0.0_r37 --depth=1
repo sync -j1 --fail-fast
wget https://dl.google.com/dl/android/aosp/google_devices-raven-tq2a.230305.008.f1-54772b94.tgz
tar -xzf google_devices-raven-tq2a.230305.008.f1-54772b94.tgz
./extract-google_devices-raven.sh
source build/envsetup.sh
lunch aosp_raven-user
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Generating the self signed keys:
export PATH=~/Android/Sdk/platform-tools/:$PATH
subject='/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=[email protected]'
mkdir ~/.android-certs
for x in releasekey platform shared media networkstack; do \
./development/tools/make_key ~/.android-certs/$x "$subject"; \
done
openssl pkcs8 -in ~/.android-certs/releasekey.pk8 -inform DER -out ~/.android-certs/releasekey.key -nocrypt
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Patch sign_target_files_apks.py so that it doesn't die when it can't find vendor.img
diff --git a/tools/releasetools/sign_target_files_apks.py b/tools/releasetools/sign_target_files_apks.py
index 6f96d8f6a..aacd0fd83 100755
--- a/tools/releasetools/sign_target_files_apks.py
+++ b/tools/releasetools/sign_target_files_apks.py
@@ -534,7 +534,7 @@ def ProcessTargetFiles(input_tf_zip, output_tf_zip, misc_info,
for info in input_tf_zip.infolist():
filename = info.filename
- if filename.startswith("IMAGES/"):
+ if filename.startswith("IMAGES/") and not filename.endswith(("vendor.img" , "vendor_dlkm.img")):
continue
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Build the code and sign it
make dist
sign_target_files_apks -o --default_key_mappings ~/.android-certs out/dist/*-target_files-*.zip signed-target-files.zip
img_from_target_files signed-target-files.zip signed-img.zip
./external/avb/avbtool.py extract_public_key --key ~/.android-certs/releasekey.key --output pkmd.bin
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Flash your Pixel 6 Pro, but first put it into fastboot mode
fastboot update signed-img.zip
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Wait for it to boot, then shut it down and go back into Fastboot Mode. Now we flast our self-signed key
fastboot erase avb_custom_key
fastboot flash avb_custom_key pkmd.bin
fastboot reboot bootloader
fastboot flashing lock
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Then cry when it doesn't work. I am suspicious that it might not be signing the images correctly, however I can't figure out how to check to see if my keys have been used to sign the images. Any idea how to verify that? Anything else I can check to eliminate potential problems? I've also flashed both A and B slots which did nothing.

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I am aware of the guide for LineageOS. Did try a few suggestions from there, like patching the Makefile, and it didn't make any difference.