$ git clone -n https://src.fedoraproject.org/rpms/rust-gtk-sys.git /var/lib/mock/f38-build-side-43-rust-devel-1397453-31052/root/chroot_tmpdir/scmroot/rust-gtk-sys
Cloning into '/var/lib/mock/f38-build-side-43-rust-devel-1397453-31052/root/chroot_tmpdir/scmroot/rust-gtk-sys'...
$ git fetch origin a70278e5ed57e2cc9c72be0c56528670ba4beee7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gtk-sys
 * [new ref]         a70278e5ed57e2cc9c72be0c56528670ba4beee7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a70278e Update to version 0.18.0; Fixes RHBZ#2231720