Regex for space substitution

[drewavis]

Hi, I'm trying to write a substitution rule for multiple spaces at the end of a sentence after a punctuation mark. Here is what I've been trying:

---
extends: substitution
message: "Use '%s' instead of '%s'"
level: error
ignorecase: false
swap:
  '(\p{P} ) ': $1

If I use anything other than $1, this regex compiles and works. However, with $1 it does not work. Any idea what is going wrong here? According to the docs $1 should work for a capture group.

[jdkato]

This is a bug. It will be fixed in the next release.