$ git clone -n https://src.fedoraproject.org/rpms/perl-POSIX-2008.git /var/lib/mock/f45-build-25639-612/root/chroot_tmpdir/scmroot/perl-POSIX-2008
Cloning into '/var/lib/mock/f45-build-25639-612/root/chroot_tmpdir/scmroot/perl-POSIX-2008'...
$ git fetch origin c3789adafea32b4f11d2fdc97fb910eb2c6cc97f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-POSIX-2008
 * [new ref]         c3789adafea32b4f11d2fdc97fb910eb2c6cc97f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c3789ad 0.28 bump