On 3 Jan 2020, at 05:07, Quinn Comendant <quinn@strangecode.com> wrote:

Thanks. By process of elimination, I was able to narrow the problem down to a language grammar I had modified: `Mail.tmbundle/Syntaxes/Email Address.tmLanguage`.

I changed this:

(?i)\b([A-Z][A-Z0-9._%+-]+)@([A-Z0-9.\-]+)\.([A-Z]{2,4})\b

To this:

(?i)\b([A-Z0-9][A-Z0-9._%+-]+)+@([A-Z0-9.\-]+)\.([A-Z]{2,4})\b

Which apparently causes infinite parsing, although I can't see why.