$ git clone -n https://src.fedoraproject.org/rpms/opencomposite.git /var/lib/mock/f42-build-side-1-3504333-45983/root/chroot_tmpdir/scmroot/opencomposite
Cloning into '/var/lib/mock/f42-build-side-1-3504333-45983/root/chroot_tmpdir/scmroot/opencomposite'...
$ git fetch origin 25771a7da7a3eb59d3f77dbeccc71831a704a5b9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/opencomposite
 * [new ref]         25771a7da7a3eb59d3f77dbeccc71831a704a5b9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 25771a7 Update to 1.0.1506 (fedora#2356499).