bug#41627: 28.0.50; Emacs with cairo build segfault in HELLO file

[Eli Zaretskii]

> Date: Tue, 23 Jun 2020 00:47:30 +0800 (CST)
> From: "Zhu Zihao" <all_but_last@163.com>
> Cc: eliz@gnu.org
> 
> I'm able to reproduce this bug in NixOS 20.03 with Emacs 27.0.91 pretest 
> version. I guess this bug is
> caused by the mechanism of Nix/Guix. NixOS doesn't have FHS directory 
> structure, it means that there's
> nothing like /usr/share/fonts for Cairo to search fonts. And I try to copy 
> some fonts to ~/.local/share/fonts
> then Emacs won't crash again.

If you can show a backtrace from the crash, perhaps we could find the
reason and fix it.

Thanks.