$ git clone -n https://src.fedoraproject.org/rpms/libguestfs.git /var/lib/mock/f39-build-1786694-41718/root/chroot_tmpdir/scmroot/libguestfs
Cloning into '/var/lib/mock/f39-build-1786694-41718/root/chroot_tmpdir/scmroot/libguestfs'...
$ git fetch origin 0d42c50ccca0cf372e9aa7e9c491f75247024cab:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libguestfs
 * [new ref]         0d42c50ccca0cf372e9aa7e9c491f75247024cab -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0d42c50 Fix date in changelog