Re: Compile issues

[Richard Stallman]

    `compilation-error-regexp-alist' is now apparently incompatible with
    the old version, but users or external packages are likely to rebind
    it.  This change isn't documented, and it's not clear to me what you
    should do instead.

Is it necessary to change this variable incompatibly?

If it is very hard to maintain compatibility in the new design, the
benefits are sufficient to justify the incompatible change.  But can
we get both the improvements and compatibility?