Seeing output running out of sources related to CoreText

[bpasero]

2020-05-26 18:11:47.989 Code - OSS Helper (Renderer)[40222:1396462] CoreText note: Client requested name ".NewYork-Regular", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2020-05-26 18:11:47.989 Code - OSS Helper (Renderer)[40222:1396462] CoreText note: Set a breakpoint on CTFontLogSystemFontNameRequest to debug.
2020-05-26 18:11:47.995 Code - OSS Helper (Renderer)[40222:1396462] CoreText note: Client requested name ".NewYork-Regular", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2020-05-26 18:11:47.998 Code - OSS Helper (Renderer)[40222:1396462] CoreText note: Client requested name ".NewYork-Regular", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2020-05-26 18:11:47.998 Code - OSS Helper (Renderer)[40222:1396462] CoreText note: Client requested name ".NewYork-Regular", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].

[starpit]

fwiw, we see this on Electron 10 as well. We only see it when monaco-editor is loaded into our application. Excluding monaco-editor, we never see this message. Perhaps the font monaco-editor uses for its dingbats is causing this?

[martonlanga]

Same using Electron v12 w/ monaco-editor

[ysfscream]

Electron: v11
Monaco-editor: v0.25.2
monaco-editor-webpack-plugin: v4.0.0
MacOS: BigSur 11.4

This problem also occurs in the above environment.

[BlackHole1]

I have spent some time investigating this issue. The problem was found to be caused by chromium.

Reproduction code:

@font-face {
  font-family: system;
  font-style: normal;
  font-weight: 300;
  src: local(".NewYork-Regular");
}
h1 {
  font-family: "system";
}

From Xcode 11 onwards, this warning will be raised.
This problem is still present in the latest Chrome.

In electron-fiddle:

gist: https://gist.github.com/BlackHole1/ca89d41a5469b0d80be9362c6b62487b

1.mp4

In chrome:

gist: https://gist.github.com/BlackHole1/91a22621ac4f912d85235850d2eafdc6

2.mp4

---

crbug link: https://bugs.chromium.org/p/chromium/issues/detail?id=1131559

---

Causes of this problem:

This warning is triggered as soon as CTFontCreateWithName or [UIFont fontWithName:fontName size:fontSize] is used.

[BlackHole1]

At the moment I see that the chromium team doesn't know how to reproduce the problem and I will go and talk to them.