$ git clone -n https://src.fedoraproject.org/rpms/rust-pkg-config.git /var/lib/mock/f45-build-43917-809/root/chroot_tmpdir/scmroot/rust-pkg-config
Cloning into '/var/lib/mock/f45-build-43917-809/root/chroot_tmpdir/scmroot/rust-pkg-config'...
$ git fetch origin c760a38d5fded7a418118e0ea705a18e350a1714:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-pkg-config
 * [new ref]         c760a38d5fded7a418118e0ea705a18e350a1714 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c760a38 Update to version 0.3.34; Fixes RHBZ#2515973