$ git clone -n https://src.fedoraproject.org/rpms/rust-grep-printer.git /var/lib/mock/f38-build-side-43-rust-devel-1397983-31057/root/chroot_tmpdir/scmroot/rust-grep-printer
Cloning into '/var/lib/mock/f38-build-side-43-rust-devel-1397983-31057/root/chroot_tmpdir/scmroot/rust-grep-printer'...
$ git fetch origin 10f8205fb3628050083bba5187b1fc1312fa7297:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-grep-printer
 * [new ref]         10f8205fb3628050083bba5187b1fc1312fa7297 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 10f8205 Update to version 0.1.7; Fixes RHBZ#2158502