No dtbo.avb.json

[roninspin]

When unpacking an Android 15 dtbo.img (Red Magic 10 Pro, SM8750) it doesn't create dtbo.avb.json, even though it mentions it in the unpack summary:

		Unpack Summary of dtbo.img

┌───────────────────────────────────────┬─────────────────────────────────────┐
│What │Where │
└───────────────────────────────────────┴─────────────────────────────────────┘
┌───────────────────────────────────────┬─────────────────────────────────────┐
│image info │build/unzip_boot/dtbo.json │
├───────────────────────────────────────┼─────────────────────────────────────┤
│device-tree blob (37 blobs) │build/unzip_boot/dt/dt.* │
│-- device-tree source │build/unzip_boot/dt/dt.*.dts │
├───────────────────────────────────────┼─────────────────────────────────────┤
│AVB info │build/unzip_boot/dtbo.avb.json │
└───────────────────────────────────────┴─────────────────────────────────────┘
┌───────────────────────────────────────┬─────────────────────────────────────┐
│vbmeta.img │build/unzip_boot/vbmeta.avb.json │
└───────────────────────────────────────┴─────────────────────────────────────┘
In fact there's only vbmeta.avb.json.

And when I repack it I get this error:

16:46:38.178 [main] INFO cfig.bootimg.Signer - Adding hash_footer with verified-boot 2.0 style
Exception in thread "main" java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:569)
at kotlin.reflect.jvm.internal.calls.CallerImpl$Method.callMethod(CallerImpl.kt:97)
at kotlin.reflect.jvm.internal.calls.CallerImpl$Method$Instance.call(CallerImpl.kt:113)
at kotlin.reflect.jvm.internal.KCallableImpl.call(KCallableImpl.kt:108)
at cfig.packable.PackableLauncherKt.main(PackableLauncher.kt:144)
Caused by: java.io.FileNotFoundException: build/unzip_boot/dtbo.avb.json (No such file or directory)
at java.base/java.io.FileInputStream.open0(Native Method)
at java.base/java.io.FileInputStream.open(FileInputStream.java:216)
at java.base/java.io.FileInputStream.(FileInputStream.java:157)
at com.fasterxml.jackson.core.TokenStreamFactory._fileInputStream(TokenStreamFactory.java:262)
at com.fasterxml.jackson.core.JsonFactory.createParser(JsonFactory.java:1030)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3542)
at cfig.bootimg.Signer$Companion.signAVB(Signer.kt:35)
at rom.fdt.Dtbo.sign(Dtbo.kt:245)
at cfig.packable.DtboParser.pack(DtboParser.kt:57)
... 8 more

If I flash unsigned dtbo (dtbo.img.clear) the phone gets stuck at the boot animation.
I tried repacking vendor_boot and init_boot before and it worked.

dtbo_a.img.txt (remove .txt)