Setting up LD_LIBRARY_PATH in the envvars seems the best way to go in my case then, with the need to avoid a system-wide install. Good to have understood the options better.
w.r.t. Apache httpd, there is an installed script called apachectl. This is the script you want to modify for additional LD_LIBRARY_PATH's and other runtime tweaks.
Still don’t get why pcre is found in the location provided but not openssl. 🤷♂️
Every package does things their own way, but either a pkgconfig description exists to describe the compile and link time option flags or there might be {package}-config script to retrieve that info. The apr and httpd projects use 12 different ways to Sunday to get at this info and it varies from dependency to dependency. And the details in the pkgconfig flags vary considerably from package to package and their release to release (and also tweaked by distribution to add extra surprises.)
So it's probably that pkgconfig for pcre sets up the -R path, while openssl you are building does not, or httpd failed to interrogate and consume that pkgconfig input in the openssl case, but did the right thing for pcre.
