Dear sbuild maintainers:

My use case is to produce a couple of files from the building process,
generated by debsbom, taking the chroot as input.  Probably the fix for
the bug is not the best way to address my use case, but anyway.  Please
consider the following commands:

sudo apt install python3-cyclonedx-lib python3-spdx-tools debsbom
TEMP_DIR=$(mktemp -d)
cd ${TEMP_DIR}
sbuild --dist=sid --post-build-commands="debsbom generate -t cdx --out - --root %SBUILD_CHROOT_DIR > ./sbom.cdx.json ; debsbom generate -t spdx --out - --root %SBUILD_CHROOT_DIR > ./sbom.spdx.json" debusine

I would expect to have these couple of files created:

${TEMP_DIR}/sbom.cdx.json
${TEMP_DIR}/sbom.spdx.json

However, the files are created in my $HOME.  Of course, this overwrites
existing sbom.{cdx,spdx}.json that I may have there.

Thanks for maintaining sbuild!