Re: Font setting issue in recent emacs dev version

[Tim Cross]

Po Lu <luangruo@yahoo.com> writes:

> Eli Zaretskii <eliz@gnu.org> writes:
>
>> The only change since 83fbda715973f57dc49fe0 that could be somehow
>> relevant is the one that touches the support for XSETTINGS on some
>> configurations.  (If you had reported this as a bug, the bug report
>> would have included the details of your configuration, and I could
>> then see if those changes could be relevant, instead of
>> hypothesizing.)  If that is indeed the offending changeset, then I
>> guess the issue has something to do with your system-wide font
>> settings.
>>
>> In any case, bisection would be appreciated.
>
> Indeed.  If you haven't changed your display scale settings with Emacs
> running, I fail to see how the xsettings changes could be related.

This has turned out a little intriguing.

Based on Eli's suggestion it could be a local X setting issue, I
rebooted and ran 'fc-cache -v' and the issue seems to have gone away.

It would seem that something which has changed between revision
83fbda715973f5 and revision ce527464440ca070e752c has made Emacs more
'sensitive' to local font settings issues. Unfortunately, there is
nothing in the messages buffer or journalctl logs which sheds any light
on what the underlying issue was. 

Prior to the reboot, Emacs from the earlier revision had no problems
loading the font I was requesting (it is a font installed within the
user's local font directory).  However, later revisions failed and fell
back to a Noto font. I was able to reproduce this behaviour reliably
using an init.el file which only had the set-face-attribute setting.

Since the reboot and running of fc-cache, I can no longer reproduce the
issue, so I guess it will remain an unexplained mystery.