There is a new pull request by gcat432 against master on the void-packages repository

https://github.com/gcat432/void-packages crystal-0.31.0
https://github.com/void-linux/void-packages/pull/14688

crystal: update to 0.31.0.
- Compilation was locally tested with both i686 and x86_64
- Package was locally installed on x86_64, `crystal` and `shards` work good
- Issue with multi-threading: it is not possible to compile with the `-Dpreview_mt` flag. Investigating the [issue](https://github.com/crystal-lang/crystal/issues/8213) someone else had on Arch.

A patch file from https://github.com/void-linux/void-packages/pull/14688.patch is attached