I have the following in my environment:

LC_ALL=en_US.utf8
LC_COLLATE=en_US.UTF-8
LC_CTYPE=en_US.UTF-8
LC_MESSAGES=en_US.UTF-8

When I run 'make check' for bleeding-edge Coreutils, I get a failure due to 
recent changes in expr. tests/misc/expr.log is attached. Evidently the recent 
changes are not taking message translation into account.

My platform is Fedora 26 x86-64.