About a year ago, I learned here that libpcre is going to disappear; the newer libpcre2 is its replacement. At the time, @tobil4sk kindly created an OCaml wrapper for libpcre2, and I upgraded all my packages to use that instead.
Except for one package, pa_ppx_regexp, which provides PPX syntax extensions for using regexps. It supports re, pcre, and pcre2. I left in pcre support, b/c I figured, pcre wasn’t gone yet, and maybe it’d be nice to leave it in.
But in the fullness of time, it seems that libpcre is disappearing (I got an OPAM-CI failure that was b/c the Debian package wasn’t available in the CI Docker image), so maybe it’s time to aggressively remove libpcre support ?