$ git clone -n https://src.fedoraproject.org/rpms/rust-fastrand.git /var/lib/mock/f45-build-41590-784/root/chroot_tmpdir/scmroot/rust-fastrand
Cloning into '/var/lib/mock/f45-build-41590-784/root/chroot_tmpdir/scmroot/rust-fastrand'...
$ git fetch origin e0402088cb8e08e755c5ee947a31ac6f067b384d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-fastrand
 * [new ref]         e0402088cb8e08e755c5ee947a31ac6f067b384d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e040208 Update to version 2.5.0; Fixes RHBZ#2502269