bug#10828: [RFC] POSIX will say running "rm -f" with no argument is OK

[Karl Berry]

    it probably comes down to being a bit clearer on what autotools'
    goals are and what it considers reasonable prerequisites.

I'd find it hard to define precisely. As a general rule, I wouldn't want
to lose support for any system that is working now, until we can be
really sure that it is no longer in use anywhere.

For me, compatibility is the dominant criterion for any change.

I made a foolish mistake recently wrt Python variables (a nice new
feature, but I failed to ensure that existing behavior did not change),
but hopefully it is back to normal in 1.16.5.

    about whether it can use POSIX shell features that have been
    standardized for over 30 years.  it has decided that it cannot for
    some.
    
And thank goodness that misguided $(...) change finally got reverted.

    clearly it's not "anything in the latest POSIX standard is fair
    game, and anything not supporting the latest POSIX standard is SOL".

Clearly, and thank goodness for that too :).

Thanks,
Karl