Emojis and CJK characters not rendered properly in Opengraph image

[CratesRadar]

Current Behavior

The crates.io opengraph images render emojis and CJK characters as square boxes

Example:

Source: https://t.me/CratesRadar/1503

Opengraph image url: https://static.crates.io/og-images/lynn_sundial.png

Expected Behavior

Special characters in crate description should be rendered normally

Steps To Reproduce

1. Find a crate where the description contains CJK characters or emojis, like lynn_sundial or sea-query
2. Visit the opengraph image url, like https://static.crates.io/og-images/lynn_sundial.png or https://static.crates.io/og-images/sea-query.png
3. Verify that ascii characters are properly rendered:

Environment

• Browser: Chrome 139
• OS: macOS 15.6

Anything else?

I made https://t.me/s/CratesRadar to monitor crates.io package updates and discovered the issue by skimming through the og images in the telegram channel

Since the images are generated from the server, it is clearly not a client-side issue. Most likely the image generation service doesn't have Chinese fonts installed.

[Turbo87]

Thanks for the bug report. This is absolutely unintentional.

As you can see in rust-lang/crates_io_og_image#24, I've started to debug this and it looks like this was primarily caused by our usage of the --ignore-system-fonts option of Typst. This apparently disabled the usage of fallback fonts for things like emoji and CJK characters. We discovered a secondary cause on our CI system, which only has a fallback font for emoji, but not for CJK characters. We will deploy the fix to the primary issue to production soon and then check what the situation is there.

[Turbo87]

We now have all the necessary puzzle pieces in place to fix this. Once #11867 is deployed to production, any new publishes for the mentioned packages should trigger a rerender of the OpenGraph image, which should then fix the CJK rendering issue since the necessary fonts are now available on our servers.

[Turbo87]

I manually triggered a rerender for the lynn_sundial and sea-query crates. Seems like the issue is fixed :)