$ git clone -n https://src.fedoraproject.org/rpms/swift-lang.git /var/lib/mock/f40-build-780169-130698/root/chroot_tmpdir/scmroot/swift-lang
Cloning into '/var/lib/mock/f40-build-780169-130698/root/chroot_tmpdir/scmroot/swift-lang'...
$ git fetch origin 77885c532d3786061eb733e374547495958ee5c4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/swift-lang
 * [new ref]         77885c532d3786061eb733e374547495958ee5c4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 77885c5 Forgot to increment the version number