[MM3-users] Mailman 3 on RHEL 7 help

Hi. I am trying to install mailman 3 on RHEL7. Docker install is not a possibility. I am trying to install it using a bundler by following https://media.readthedocs.org/pdf/mailman-bundler/stable/mailman-bundler.pdf, but after logging in as mailman, I can't do virtualenv venv. It works if I login as root, but still fails during buildout.

In short, I need help. Has anyone of you guys installed mailman 3 on RHEL 7 or CEntOS 7? If so would you share me detailed instructions? Thank you in advance.