From our documentation:

If you wish to use any of the meta-characters ( such as !"#$%&'()*+,./:;<=>?@[\\]^`{|}~ ) as a literal part of a name, you must escape the character with two backslashes: \\\\

Applying this to your selector results in a test case that works fine: https://jsfiddle.net/WpGGh/

ok, I missed that point in the documentation.

I'll change my code accordingly.

Thanks a lot.

https://github.com/jquery/sizzle/pull/133

Update Sizzle to fix #12082, #12087.

Changeset: f70a696598f14917e49dc108271788e2ec2f6587