Bug in NetBSD grep ?

[Marc Baudoin <babafou%babafou.eu.org@localhost>]

Hi,

The following command-line:

echo 00:00: | grep -E '^([0]{2}[:-]){2}$'

doesn't print anything on NetBSD (9.3) but it prints 00:00: back
(as it should, unless I made a mistake in my regular expression):
- on NetBSD with GNU grep from pkgsrc
- on FreeBSD with their standard grep (which claims to be
  GNU-compatible)
- on Linux (with GNU grep)

Is there a problem with the grep command shipped with NetBSD?