Re: cperl-mode: Eliminating references to obsolete packages

[Stefan Monnier <monnier@iro.umontreal.ca>]

> The point of *this* post was to actually _eliminate_ some fboundp
> conditionals in cperl-mode.el, so it feels a bit weird to introduce a
> new one in the same step.

Either way is fine by me.

> But replacement of deprecated / old stuff does occasionally happens
> across the Emacs repository.

Yes.

> This may hit cperl-mode.el at any time, like it did with time-convert
> and format-prompt.  So, every now and then, the Emacs repository will
> contain a cperl-mode.el which won't work with Emacs 26, until someone
> notices it and someone prepares another backporting-patch.

That's right.  We have that problem for all 17 current GNU ELPA packages
distributed directly from the `emacs.git` repository.

For example that "format-prompt" problem currently also affects the
python.el GNU ELPA package.  Luckily, AFAICT we haven't yet released
a new python.el package (because the version number has not been
bumped), but the problem is real.

In practice it hasn't been too problematic, in part because it's very
easy to make/distribute/download/install a new release that fixes
the problem.

> Or until cperl-mode.el gets a place or procedure where these changes
> don't hit.

Some automated tests that try to build&compile (and treat warnings as
errors) those packages on the corresponding oldest Emacs version
supported would come in handy.


        Stefan