$ git clone -n https://src.fedoraproject.org/rpms/rust-gio-sys0.21.git /var/lib/mock/f45-build-41862-786/root/chroot_tmpdir/scmroot/rust-gio-sys0.21
Cloning into '/var/lib/mock/f45-build-41862-786/root/chroot_tmpdir/scmroot/rust-gio-sys0.21'...
$ git fetch origin 7a7cc222f08e221bb1d4adca1526b72f96801156:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gio-sys0.21
 * [new ref]         7a7cc222f08e221bb1d4adca1526b72f96801156 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7a7cc22 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild