test-build-all fails to flag binary-all ftbfs

Greetings,

I had a test-build-all job pass for altree on a tag which turned out to be affected by Bug#1115489 about binary-all FTBFS. Having a close look at the whole build log, I noticed the build command was:

BUILD_COMMAND=sbuild --dist=unstable --no-clean-source  --arch-all --build-dir=/builds/med-team/altree/debian/output --no-run-lintian --verbose

However, I also noticed that I needed to pass a flag --no-arch-any in addition to --arch-all to sbuild if I wanted to reproduce the Bug#1115489:

$ sbuild --arch-all # builds, --arch-any behavior slightly surprizing
$ sbuild --arch-all --no-arch-any # ftbfs, as expected

and I noticed that the --no-arch-any was missing from the build command.

Please could you restore the provision of --no-arch-any to the sbuild command in the context of the test-build-all test of the default CI?

Note also that I have not checked the status of test-build-any, but I suppose it could be affected by a similar issue.

Have a nice day, :)
Étienne.