This can be done without the need for the rpm-build package (which provides the rpmspec command) using the query:

    $ rpm -q --specfile --requires openshift-origin-cartridge-phpmyadmin.spec 
    rubygem(openshift-origin-node)
    openshift-origin-node-util
    httpd > 2.3
    httpd < 2.5
    phpMyAdmin < 3.6
    phpMyAdmin >= 3.4
    /bin/sh

    $ rpmspec -q --requires openshift-origin-cartridge-phpmyadmin.spec 
    rubygem(openshift-origin-node)
    openshift-origin-node-util
    httpd > 2.3
    httpd < 2.5
    phpMyAdmin < 3.6
    phpMyAdmin >= 3.4
    /bin/sh