$ git clone -n https://src.fedoraproject.org/rpms/pmbootstrap.git /var/lib/mock/f41-build-side-1-3128641-39569/root/chroot_tmpdir/scmroot/pmbootstrap
Cloning into '/var/lib/mock/f41-build-side-1-3128641-39569/root/chroot_tmpdir/scmroot/pmbootstrap'...
$ git fetch origin 4ec3c36880990d48554ad52ac9ee4985e18e1ab8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/pmbootstrap
 * [new ref]         4ec3c36880990d48554ad52ac9ee4985e18e1ab8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4ec3c36 Exclude the valid_chroots test on non x86_64