$ git clone -n https://src.fedoraproject.org/rpms/rust-diesel.git /var/lib/mock/f42-build-side-1-3539439-46565/root/chroot_tmpdir/scmroot/rust-diesel
Cloning into '/var/lib/mock/f42-build-side-1-3539439-46565/root/chroot_tmpdir/scmroot/rust-diesel'...
$ git fetch origin ac28e815a250862cf4fe3eba39335a0c8876402f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-diesel
 * [new ref]         ac28e815a250862cf4fe3eba39335a0c8876402f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ac28e81 Update to version 2.2.10; Fixes RHBZ#2357481