$ git clone -n https://src.fedoraproject.org/rpms/rust-libgit2-sys.git /var/lib/mock/f45-build-42920-797/root/chroot_tmpdir/scmroot/rust-libgit2-sys
Cloning into '/var/lib/mock/f45-build-42920-797/root/chroot_tmpdir/scmroot/rust-libgit2-sys'...
$ git fetch origin d7698324a0754040f3a8f0aba286efea9ff87344:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-libgit2-sys
 * [new ref]         d7698324a0754040f3a8f0aba286efea9ff87344 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d769832 Update to version 0.18.8; Fixes RHBZ#2521216