Re: Byte-compilation of custom themes

[Eli Zaretskii <eliz@gnu.org>]

> From: "Basil L. Contovounesios" <contovob@tcd.ie>
> Cc: <monnier@IRO.UMontreal.CA>,  <emacs-devel@gnu.org>
> Date: Fri, 01 Jun 2018 21:48:21 +0100
> 
> >> Do you mean a cl-assertion, or an emulation thereof?
> >
> > I meant cl-assert.
> 
> Unless I (being unfamiliar with the subtleties of the build and
> bootstrap process) am missing something, I think it's too early to load
> cl-lib here; at least 'make bootstrap' fails for me when I add
> (eval-when-compile (require 'cl-lib)) to custom.el.  Is there a way
> around this?

Yes, explicitly check whether cl-lib is available, and skip the call
if not.  We don't need this assertion during the bootstrap.

> >> Either way, what is the benefit of barfing before directory-files does?
> >
> > That you can control the text of the error message, and make it more
> > user-friendly.  Also, an assertion clearly means we intended this not
> > to happen, rather than that the code failed to handle some valid
> > situation.
> 
> Understood.  I've noticed, however, that many, if not most, uses of
> cl-assert don't specify a custom error message.  For future reference,
> is this acceptable practice, or would we rather see consistent use of
> more informative messages?

My preference is clear from the above, but I don't have enough
experience to answer the rest of your question.

Thanks.