I've just encountered this same “Bad CPU type” error with ruby18:

/Users/quinn/Library/Application Support/TextMate/Managed/Bundles/Bundle Support.tmbundle/Support/shared/bin/ruby18: line 43: /Users/quinn/Library/Application Support/TextMate/Ruby/1.8.7/bin/ruby: Bad CPU type in executable
/Users/quinn/Library/Application Support/TextMate/Managed/Bundles/Bundle Support.tmbundle/Support/shared/bin/ruby18: line 43: /Users/quinn/Library/Application Support/TextMate/Ruby/1.8.7/bin/ruby: Undefined error: 0

1. I upgraded to a MBP 14", running macOS 12.1 (clean install).
2. I fresh-installed TextMate via brew install text mate
3. I tried running my Duplicate Line command: https://pastebin.com/G8HLz4tc
4. I get the error above.

This command doesn't work with ruby v2, so it can't be fixed as easy as Christophe's ruby18 wrapper script hack.

Should the ruby18 included in TextMate be able to run on Apple silicon?

Regards,
Quinn