This bug has the feel of Bug#25707, which was fixed as described in:
http://bugs.gnu.org/25707Can you try a grep with that fix? Here's one way to build and test grep with the fix, assuming you have sufficient developer tools installed:
git clone https://git.savannah.gnu.org/git/grep.git cd grep ./bootstrap ./configure make echo rr/| src/grep '^.*\/$'
