Building the current grep (git master) with the current Gnulib on Cygwin 3.5.3, I see a test failure:
FAIL: backref-multibyte-slow The detailed log is attached. Bruno
log.gz
Description: application/gzip
- bug#71468: backref-multibyte-slo... Bruno Haible
- bug#71468: backref-multibyt... Collin Funk
- bug#71468: backref-mult... Bruno Haible via Bug reports for GNU grep
