For example:
# ADDITIONAL_GUIX_COMMON_FLAGS set in the ENV
ADDITIONAL_GUIX_ENVIRONMENT_FLAGS="--emulate-fhs" ./contrib/guix/guix-build
<snip>
INFO: Building f751991 for platform triple x86_64-linux-gnu:
...using reference timestamp: 1716905119
...running at most 10 jobs
...from worktree directory: '/bitcoin'
...bind-mounted in container to: '/bitcoin'
...in build directory: '/bitcoin/guix-build-f75199182133/distsrc-f75199182133-x86_64-linux-gnu'
...bind-mounted in container to: '/distsrc-base/distsrc-f75199182133-x86_64-linux-gnu'
...outputting in: '/bitcoin/guix-build-f75199182133/output/x86_64-linux-gnu'
...bind-mounted in container to: '/outdir-base/x86_64-linux-gnu'
ADDITIONAL FLAGS (if set)
ADDITIONAL_GUIX_COMMON_FLAGS: --no-substitutes
ADDITIONAL_GUIX_ENVIRONMENT_FLAGS: --emulate-fhs
ADDITIONAL_GUIX_TIMEMACHINE_FLAGS: