From https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1000134:

``` Source: kamailio Severity: important User: matthew-pcredep@debian.org Usertags: obsolete-pcre3

Dear maintainer,

Your package still depends on the old, obsolete PCRE3[0] libraries (i.e. libpcre3-dev). This has been end of life for a while now, and upstream do not intend to fix any further bugs in it. Accordingly, I would like to remove the pcre3 libraries from Debian, preferably in time for the release of Bookworm.

The newer PCRE2 library was first released in 2015, and has been in Debian since stretch. Upstream's documentation for PCRE2 is available here: https://pcre.org/current/doc/html/

Many large projects that use PCRE have made the switch now (e.g. git, php); it does involve some work, but we are now at the stage where PCRE3 should not be used, particularly if it might ever be exposed to untrusted input.

This mass bug filing was discussed on debian-devel@ in https://lists.debian.org/debian-devel/2021/11/msg00176.html

Regards,

Matthew [0] Historical reasons mean that old PCRE is packaged as pcre3 in Debian ```