Building grep-3.11 on FreeBSD 14.0, "make check" reports that the fmbtest
test is skipped:

  fmbtest: skipped test: this system lacks the cs_CZ.UTF-8 locale
  SKIP: fmbtest

But

  $ locale -a | grep cs_CZ
  cs_CZ.ISO8859-2
  cz_CZ.UTF-8

shows that the system does have this locale.

The cause is that this invocation of 'locale' does not work:

  $ locale -k LC_CTYPE
  Unknown keyword: `LC_CTYPE`

But this one works:

  $ locale charmap
  UTF-8

=> Patch attached. It fixes the problem: it makes the test PASS.

'locale charmap' is known to work portably for ages; see
https://git.savannah.gnu.org/gitweb/?p=libiconv.git;a=tree;f=libcharset/tools;h=f756e65e5ea8fef47afc8bb7ae1094e169012c78;hb=HEAD