Improve WebGL font error message to suggest textFont() usage by yugalkaushik · Pull Request #8494 · processing/p5.js
If the test runs, then this sounds reasonable and helpful! I checked the failing test and I'm not sure what was up, I reran. If it fails, then code would need to be updated so tests do pass.
Minor wording revision to keep the message same length:
WEBGL: requires Opentype (.otf) or Truetype (.ttf) font, loaded using textFont() before drawing text.