Do not add default matplotlib font, but rely on the default LaTeX font.

oscargus · oscargus · commit 09c5cb39a1e1 · 2022-07-07T09:53:02.000+02:00
diff --git a/examples/userdemo/pgf_fonts.py b/examples/userdemo/pgf_fonts.py
@@ -4,7 +4,9 @@
 =========
 """
 
+import matplotlib as mpl
 import matplotlib.pyplot as plt
+mpl.use("pgf")
 plt.rcParams.update({
     "font.family": "serif",
     # Use LaTeX default serif font.
diff --git a/lib/matplotlib/backends/backend_pgf.py b/lib/matplotlib/backends/backend_pgf.py
@@ -65,11 +65,18 @@ def _get_preamble():
             families = ["serif", "sans\\-serif", "monospace"]
             commands = ["setmainfont", "setsansfont", "setmonofont"]
             for family, command in zip(families, commands):
-                # 1) Forward slashes also work on Windows, so don't mess with
-                # backslashes.  2) The dirname needs to include a separator.
-                path = pathlib.Path(fm.findfont(family))
-                preamble.append(r"\%s{%s}[Path=\detokenize{%s/}]" % (
-                    command, path.name, path.parent.as_posix()))
+                try:
+                    # 1) Forward slashes also work on Windows, so do not mess
+                    # with backslashes.
+                    # 2) The dirname needs to include a separator.
+                    path = pathlib.Path(fm.findfont(family,
+                                                    fallback_to_default=False))
+                except ValueError:
+                    # Use default LaTeX font instead
+                    pass
+                else:
+                    preamble.append(r"\%s{%s}[Path=\detokenize{%s}]" % (
+                        command, path.name, path.parent.as_posix() + "/"))
     return "\n".join(preamble)
 
 
