$ git clone -n https://src.fedoraproject.org/rpms/blueman.git /var/lib/mock/f42-build-side-1-3501574-45974/root/chroot_tmpdir/scmroot/blueman
Cloning into '/var/lib/mock/f42-build-side-1-3501574-45974/root/chroot_tmpdir/scmroot/blueman'...
$ git fetch origin 9691acee711c6e6f877bd21871b34e4c3b019029:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/blueman
 * [new ref]         9691acee711c6e6f877bd21871b34e4c3b019029 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9691ace Fix python3-gobject dependency (rhbz#2354051)