Cross build fails on Kaniko

[bearprevent]

Expected behaviour

Using a balenalib image with Kaniko should work as with Docker build.

Actual behaviour

Running the following kaniko executor command with the Dockerfile provided below will yield a link /bin/sh.real /bin/sh: no such file or directory error.

docker run --rm -it --volume ./:/test gcr.io/kaniko-project/executor:debug --context /test --dockerfile /test/Dockerfile --no-push

Error message

INFO[0000] Retrieving image manifest balenalib/armv7hf-debian-python 
INFO[0000] Retrieving image balenalib/armv7hf-debian-python from registry index.docker.io 
INFO[0001] Built cross stage deps: map[]                
INFO[0001] Retrieving image manifest balenalib/armv7hf-debian-python 
INFO[0001] Returning cached image manifest              
INFO[0001] Executing 0 build triggers                   
INFO[0001] Building stage 'balenalib/armv7hf-debian-python' [idx: '0', base-idx: '-1'] 
INFO[0001] Unpacking rootfs as cmd RUN ["cross-build-start"] requires it. 
INFO[0006] RUN ["cross-build-start"]                    
INFO[0006] Initializing snapshotter ...                 
INFO[0006] Taking snapshot of full filesystem...        
INFO[0010] Cmd: /usr/bin/cross-build-start              
INFO[0010] Args: []                                     
INFO[0010] Running: [/usr/bin/cross-build-start]        
2023/03/20 09:31:22 link /bin/sh.real /bin/sh: no such file or directory
error building image: error building stage: failed to execute command: waiting for process to exit: exit status 1

Additional information

Dockerfile

FROM balenalib/armv7hf-debian-python

RUN ["cross-build-start"]

RUN pip install --upgrade pip

RUN ["cross-build-end"]

Docker build

This will work as expected:

docker build .

Kaniko executor

This will fail:

docker run --rm -it --volume ./:/test gcr.io/kaniko-project/executor:debug --context /test --dockerfile /test/Dockerfile --no-push

Workaround

I documented a workaround at kaniko #1556: I replaced resin-xbuild by a custom build of https://github.com/balena-io-library/armv7hf-debian-qemu/blob/master/resin-xbuild.go.