$ git clone -n https://src.fedoraproject.org/rpms/bismuth.git /var/lib/mock/f40-build-2603910-63358/root/chroot_tmpdir/scmroot/bismuth
Cloning into '/var/lib/mock/f40-build-2603910-63358/root/chroot_tmpdir/scmroot/bismuth'...
$ git fetch origin 4a3fb1558cf6c8b91285a5c332c7303ab0515110:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/bismuth
 * [new ref]         4a3fb1558cf6c8b91285a5c332c7303ab0515110 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4a3fb15 Unmaintained and doesn't work with Plasma 6