Plotmath on Fedora 31 broken with with pango >= 1.44 - workarounds?

On Wed, 25 Mar 2020 at 01:14, Gavin Simpson <ucfagls at gmail.com> wrote:

Dear list

On Fedora 31 the pango library has recently updated to version >= 1.44
and in doing so has switched to using the HarfBuzz library (from
FreeType) and dropped Adobe Type 1 font support. This causes problems
with plotmath as all bar one of the glyphs doesn't render (see
attached PNG image if it makes it through the list filters - if not I
have shared a copy via my google drive:
https://drive.google.com/file/d/1llFqKHD7LFKzQbVuq6sibY1UizRn7xxS/view?usp=sharing
)

I'm not the only person who has come across this, e.g.
https://stackoverflow.com/q/60656445/429846 and the resulting reported
bug on the RedHat Bugzilla:
https://bugzilla.redhat.com/show_bug.cgi?id=1815128

Beyond switching to  `type = 'Xlib'`, has anyone worked around this
issue on a Fedora 31 or later system?

Adding devel at lists.fp.o to CC. A workaround is to avoid using PS fonts
for symbols. If you run the following, you'll see

$ fc-match Symbol
StandardSymbolsPS.t1: "Standard Symbols PS" "Regular"

So let's change this. Install a TTF symbol font, such as Symbola:

$ sudo dnf install gdouros-symbola-fonts

Then add the following to /etc/fonts/local.conf (system-wide) or
~/.fonts.conf (just for your user):

<fontconfig>
<match target="pattern">
 <test name="family"><string>Symbol</string></test>
 <edit name="family" mode="prepend" binding="same">
   <string>Symbola</string>
 </edit>
</match>
</fontconfig>

Now you should see this:

$ fc-match Symbol
Symbola.ttf: "Symbola" "Regular"

and symbols should render correctly.

I?aki