$ git clone -n https://src.fedoraproject.org/rpms/rust-devicemapper-sys.git /var/lib/mock/f39-build-1534473-36233/root/chroot_tmpdir/scmroot/rust-devicemapper-sys
Cloning into '/var/lib/mock/f39-build-1534473-36233/root/chroot_tmpdir/scmroot/rust-devicemapper-sys'...
$ git fetch origin 21a65423ebad7642f73d046f1f13c440d6bba1bd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-devicemapper-sys
 * [new ref]         21a65423ebad7642f73d046f1f13c440d6bba1bd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 21a6542 Update to version 0.2.0