bug#61014: 29.0.60; flymake-mode stderr warning is confusing when edit the init.el or eary-init.el

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: João Távora <joaotavora@gmail.com>,
>   aqua0210@foxmail.com,
>   61014@debbugs.gnu.org
> Date: Thu, 02 Feb 2023 11:01:20 -0500
> 
> > How about disabling this warning in non-interactive sessions?  That
> > should be easy, and I don't see why we would want to emit such a
> > warning in non-interactive sessions anyway.
> 
> Before making any change, I'd wait to see some explanation about why
> this message in a hidden " *stderr of elisp-flymake-byte-compile*" buffer
> is a problem.

I don't thin it should be a problem, but I also don't see any harm in
suppressing the warning in non-interactive sessions.  That warning is
clearly meant to be presented to users when they start an interactive
session and their customizations did dubious things.

I hoped that suppressing this in non-interactive session would strike
a balance between having the warning when it matters and removing the
annoyance in the OP's case, even if the justification of that
annoyance is not necessarily clear to us.

IOW, a compromise that would leave everybody happy enough.

WDYT?