* lisp/progmodes/compile.el
(compilation-error-regexp-alist-alist): Make leading '|'
optional when there are leading spaces (bug#80681).
* etc/compilation.txt (GNU style): New error with two leading
spaces.
* test/lisp/progmodes/compile-tests.el
(compile-test-error-regexps): Increment expected
compilation-num-errors-found.
(compile-tests--test-regexps-data): New error test case for
'gnu' with two leading spaces. Change expected match for
'cucumber' to match again 'gnu'.
Copyright-paperwork-exempt: yes
eb4835e521