For some time now, I keep having problems with fonts in Emacs. In particular, the font weight is wrong. The problem surfaced some time ago (see the Doom Discourse forum), went away, and is back after a recent Nixpkgs update (unstable). Fonts and font weights are displayed fine in other applications.
Fira Code, and the font with regular weight (aka normal, medium) works just fine, but bold text is still displayed with regular weight. Further, some special characters have the wrong weight; can you see the difference:
I wanted to ask if others also have trouble with font weights in Emacs, or if you have any ideas about how to fix this problem.