$ git clone -n https://src.fedoraproject.org/rpms/guile-commonmark.git /var/lib/mock/f45-build-13237-447/root/chroot_tmpdir/scmroot/guile-commonmark
Cloning into '/var/lib/mock/f45-build-13237-447/root/chroot_tmpdir/scmroot/guile-commonmark'...
$ git fetch origin 6be1a5b5c569431ef47e2ff658951eaa83529be0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/guile-commonmark
 * [new ref]         6be1a5b5c569431ef47e2ff658951eaa83529be0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6be1a5b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild