bug#62052: _N_GNU_nonoption_argv_flags_ is no longer supported

[Emanuele Torre]

Hello.

I have noticed the _N_GNU_nonoption_argv_flags_ (where N is the pid of
grep) environment variable mentioned in the documentation. I tried to
play with it, but it does not seem to work:

 bash-5.1$ (declare -x _"$BASHPID"_GNU_nonoption_argv_flags_=1111111
 > exec grep -e)
 grep: option requires an argument -- 'e'
 Usage: grep [OPTION]... PATTERNS [FILE]...
 Try 'grep --help' for more information.

I have checked gnulib's changelog and it looks like support for it has
been removed in 2017, and before that it has not been enabled by default
since 2001. (and, as far as I can tell, GNU grep never explicitly
enabled it.)

Furthermore, this environment variable used to be set this environment
variable automatically by bash up to version 2.0, but since version 2.01
(released in 1997) bash has stopped using it.

I think, at this point, it would be best to not mention that environment
variable in the documentation; it has not been used or even supported
for a long time so it is just confusing.

Bye. :)
 emanuele6