This worked in Deno 2.5.4, but not in Deno canary anymore. It works in Chrome too.
new URLPattern({ pathname: "/install(\.sh|\.ps1)" })
Output:
Uncaught TypeError: Failed to construct 'URLPattern': pathname is invalid; Invalid regular expression: /(?u)^/install(.sh|.ps1)$/u: Invalid group
at new URLPattern (ext:deno_url/01_urlpattern.js:202:15)
at <anonymous>:1:22
Version: Deno 2.5.4+41e70e5