TTLibError: specify a font number between 0 and 5 (inclusive)

...
~/miniconda3/lib/python3.8/site-packages/matplotlib/backends/backend_pdf.py in embedTTF(self, filename, characters)
   1424             return embedTTFType3(font, characters, descriptor)
   1425         elif fonttype == 42:
-> 1426             return embedTTFType42(font, characters, descriptor)
   1427 
   1428     def alphaState(self, alpha):
...

import matplotlib.pyplot as plt
plt.plot((1,2,3))
plt.title('Axes Title', font='Helvetica')
plt.savefig('text.pdf')

---------------------------------------------------------------------------
TTLibError                                Traceback (most recent call last)
/var/folders/bj/czjbfh496258q1lc3p01lyz00000gn/T/ipykernel_58793/3096390865.py in <module>
      2 plt.plot((1,2,3))
      3 plt.title('Axes Title', font='Helvetica')
----> 4 plt.savefig('text.pdf')

~/miniconda3/lib/python3.8/site-packages/matplotlib/pyplot.py in savefig(*args, **kwargs)
    956 def savefig(*args, **kwargs):
    957     fig = gcf()
--> 958     res = fig.savefig(*args, **kwargs)
    959     fig.canvas.draw_idle()   # need this if 'transparent=True' to reset colors
    960     return res

~/miniconda3/lib/python3.8/site-packages/matplotlib/figure.py in savefig(self, fname, transparent, **kwargs)
   3010                         ax.patch._cm_set(facecolor='none', edgecolor='none'))
   3011 
-> 3012             self.canvas.print_figure(fname, **kwargs)
   3013 
   3014     def ginput(self, n=1, timeout=30, show_clicks=True,

~/miniconda3/lib/python3.8/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, pad_inches, bbox_extra_artists, backend, **kwargs)
   2312                 # force the figure dpi to 72), so we need to set it again here.
   2313                 with cbook._setattr_cm(self.figure, dpi=dpi):
-> 2314                     result = print_method(
   2315                         filename,
   2316                         facecolor=facecolor,

~/miniconda3/lib/python3.8/site-packages/matplotlib/backend_bases.py in wrapper(*args, **kwargs)
   1641             kwargs.pop(arg)
   1642 
-> 1643         return func(*args, **kwargs)
   1644 
   1645     return wrapper

~/miniconda3/lib/python3.8/site-packages/matplotlib/_api/deprecation.py in wrapper(*inner_args, **inner_kwargs)
    384             # Early return in the simple, non-deprecated case (much faster than
    385             # calling bind()).
--> 386             return func(*inner_args, **inner_kwargs)
    387         arguments = signature.bind(*inner_args, **inner_kwargs).arguments
    388         if is_varargs and arguments.get(name):

~/miniconda3/lib/python3.8/site-packages/matplotlib/backends/backend_pdf.py in print_pdf(self, filename, dpi, bbox_inches_restore, metadata)
   2786             renderer.finalize()
   2787             if not isinstance(filename, PdfPages):
-> 2788                 file.finalize()
   2789         finally:
   2790             if isinstance(filename, PdfPages):  # finish off this page

~/miniconda3/lib/python3.8/site-packages/matplotlib/backends/backend_pdf.py in finalize(self)
    792         self.endStream()
    793         self._write_annotations()
--> 794         self.writeFonts()
    795         self.writeExtGSTates()
    796         self._write_soft_mask_groups()

~/miniconda3/lib/python3.8/site-packages/matplotlib/backends/backend_pdf.py in writeFonts(self)
    925                 chars = self._character_tracker.used.get(filename)
    926                 if chars:
--> 927                     fonts[Fx] = self.embedTTF(filename, chars)
    928         self.writeObject(self.fontObject, fonts)
    929 

~/miniconda3/lib/python3.8/site-packages/matplotlib/backends/backend_pdf.py in embedTTF(self, filename, characters)
   1424             return embedTTFType3(font, characters, descriptor)
   1425         elif fonttype == 42:
-> 1426             return embedTTFType42(font, characters, descriptor)
   1427 
   1428     def alphaState(self, alpha):

~/miniconda3/lib/python3.8/site-packages/matplotlib/backends/backend_pdf.py in embedTTFType42(font, characters, descriptor)
   1230             subset_str = "".join(chr(c) for c in characters)
   1231             _log.debug("SUBSET %s characters: %s", filename, subset_str)
-> 1232             fontdata = _backend_pdf_ps.get_glyphs_subset(filename, subset_str)
   1233             _log.debug(
   1234                 "SUBSET %s %d -> %d", filename,

~/miniconda3/lib/python3.8/site-packages/matplotlib/backends/_backend_pdf_ps.py in get_glyphs_subset(fontfile, characters)
     40     options.drop_tables += ['FFTM', 'PfEd']
     41 
---> 42     with subset.load_font(fontfile, options) as font:
     43         subsetter = subset.Subsetter(options=options)
     44         subsetter.populate(text=characters)

~/miniconda3/lib/python3.8/site-packages/fontTools/misc/loggingTools.py in wrapper(*args, **kwds)
    370                         def wrapper(*args, **kwds):
    371                                 with self:
--> 372                                         return func(*args, **kwds)
    373                         return wrapper
    374                 else:

~/miniconda3/lib/python3.8/site-packages/fontTools/subset/__init__.py in load_font(fontFile, options, checkChecksums, dontLoadGlyphNames, lazy)
   3006 	      lazy=True):
   3007 
-> 3008 	font = ttLib.TTFont(fontFile,
   3009                             checkChecksums=checkChecksums,
   3010                             recalcBBoxes=options.recalc_bounds,

~/miniconda3/lib/python3.8/site-packages/fontTools/ttLib/ttFont.py in __init__(self, file, res_name_or_index, sfntVersion, flavor, checkChecksums, verbose, recalcBBoxes, allowVID, ignoreDecompileErrors, recalcTimestamp, fontNumber, lazy, quiet, _tableCache)
    141                         file = tmp
    142                 self._tableCache = _tableCache
--> 143                 self.reader = SFNTReader(file, checkChecksums, fontNumber=fontNumber)
    144                 self.sfntVersion = self.reader.sfntVersion
    145                 self.flavor = self.reader.flavor

~/miniconda3/lib/python3.8/site-packages/fontTools/ttLib/sfnt.py in __init__(self, file, checkChecksums, fontNumber)
     58                         numFonts = header.numFonts
     59                         if not 0 <= fontNumber < numFonts:
---> 60                                 raise TTLibError("specify a font number between 0 and %d (inclusive)" % (numFonts - 1))
     61                         self.numFonts = numFonts
     62                         self.file.seek(header.offsetTable[fontNumber])

TTLibError: specify a font number between 0 and 5 (inclusive)