Error configuring 8.1.5 installation

I am trying to upgrade a PHP 7.2.9 installation to PHP 8.1.5 and I'm getting an
error "No package openssl found".  openssl-1.1.1n is installed in the non-
standard location /usr/openssl-1.1.1n/  to avoid conflict with other processes
running on this server.  The suggestions I'm getting from the configure
programme suggest changing the environment which I am afraid to do since it
might crash something else that is already running on the server. 

The relevant info is:

- download version of php-8.1.5 from the PHP server

- newly installed openssl-1.1.1n on /usr/openssl-1.1.1n/ in the usual
subdirectories.  (.../bin and .../lib) This has been tested and works properly.
The version of openssl in the system path is the old one, 1.1.0k so I do need to
override it. 

- O/S is Fedora 25

Configuration file that I am using:

./configure --prefix=/usr/php-8.1.5 --with-apxs2=/usr/apache-2.4.25/bin/apxs --
enable-fpm --with-fpm-user=phpfpm --with-fpm-group=phpfpm --with-fpm-systemd --
disable-short-tags --with-openssl=/usr/openssl-1.1.1n/ --with-zlib --with-
pgsql=/usr/postgres-9.6.2 --with-pear --with-libxml-dir=/usr/lib64 

Any suggestions would be appreciated.

John
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