$ git clone -n https://src.fedoraproject.org/rpms/rust-libblkid-rs-sys.git /var/lib/mock/f42-build-side-1-3581421-46829/root/chroot_tmpdir/scmroot/rust-libblkid-rs-sys
Cloning into '/var/lib/mock/f42-build-side-1-3581421-46829/root/chroot_tmpdir/scmroot/rust-libblkid-rs-sys'...
$ git fetch origin 3a9cfe2c47b7217b01c295b992cdf376eba8de18:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-libblkid-rs-sys
 * [new ref]         3a9cfe2c47b7217b01c295b992cdf376eba8de18 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3a9cfe2 Make updates fully automatic