Why does flatpak-builder fail on different host?

I am about to update org.parlatype.Parlatype. I have a new, quite complicated setup including bootstrapping Bazel: https://github.com/gkarsay/parlatype/blob/main/flatpak/org.parlatype.Parlatype.json

I built it with

flatpak-builder --repo=parlatype-test build-dir org.parlatype.Parlatype.json

This works fine on Debian Stable (bullseye). I tried the same manifest on Debian Sid (except the main program built from archive rather than git) and Bazel builds but doesn’t work and the whole build fails.

Can you explain what might influence the build apart from different flatpak-builder versions (1.0.12 vs. 1.2.0)? The used Sdk is the same, is there anything on the host that makes a difference?

I suspect its something about these build-options:

            "build-options" : {
                "strip" : false,
                "no-debuginfo" : true,
                "no-debuginfo-compression" : true,
                "env" : {
                    "EXTRA_BAZEL_ARGS" : "--host_javabase=@local_jdk//:jdk",
                    "JAVA_HOME" : "/usr/lib/sdk/openjdk11/jvm/openjdk-11"

Is there any explanation why this would in a different way on different hosts?