Source: qtbase-opensource-src Version: 5.9.2+dfsg-4 Qt 5.9 swiched from the original PCRE to the newer PCRE2, but the build dependencies in qtbase-opensource-src were not adjusted. So now qtbase-opensource-src has an unused build dependency on libpcre3-dev, and builds with a bundled copy of PCRE2 instead.
The libpcre3-dev build dependency should be removed, and perhaps replaced with libpcre2-dev to pick up the system PCRE2. Note that Debian’s pcre2 10.22 is the same version as that bundled with Qt 5.9, but older than pcre2 10.30 bundled with Qt 5.10: https://bugs.debian.org/883224.
