yum-rhn-plugin-0.6.1-1.el5.noarch from spacewalk-testing has depsolving problems --> Missing Dependency: m2crypto >= 0.16-6.el5.6 is needed by package yum-rhn-plugin-0.6.1-1.el5.noarch (spacewalk-testing) http://ftp.redhat.com/pub/redhat/linux/enterprise/5Server/en/os/SRPMS/ isn't listing 0.16-6.el5.6 yet... el5.3 seems to be the latest listed.
Looks like a typo, plus an unecessary requires that includes a specific disttag, which makes no sense. The version in RHEL 5 is el5.3, not 5.6. Changing requires to just require a version and release in: a7ded5955210d28463794214a69aaf5cc96652ec