Previously it would result in neither pcre library being detected:
checking for getnameinfo... (cached) yes
configure: WARNING: Ignoring pcre2 even if it's available
test: =: unexpected operator
Enabling support for client-specific tags.
checking for zlibVersion in -lz... (cached) yes
Enabling compression support.
test: =: unexpected operator
test: =: unexpected operator
configure: error: Detected neither pcre2 nor pcre library.
else
AC_MSG_WARN([Ignoring pcre2 even if it's available])
try_pcre2=no
+ have_pcre2=no
fi
if test $try_pcre2 != no; then