aliBuild O2 fails on CentOs 7 during Python-modules

Dear experts,

I am trying to build O2 on CentOs7. While building Python-modules I get the following error

ERROR: Could not find a version that satisfies the requirement ipython==7.4.0 (from -r requirements.txt (line 3)) (from versions: 0.10, 0.10.1, 0.10.2, 0.11, 0.12, 0.12.1, 0.13, 0.13.1, 0.13.2, 1.0.0, 1.1.0, 1.2.0, 1.2.1, 2.0.0, 2.1.0, 2.2.0, 2.3.0, 2.3.1, 2.4.0, 2.4.1, 3.0.0, 3.1.0, 3.2.0, 3.2.1, 3.2.2, 3.2.3, 4.0.0b1, 4.0.0, 4.0.1, 4.0.2, 4.0.3, 4.1.0rc1, 4.1.0rc2, 4.1.0, 4.1.1, 4.1.2, 4.2.0, 4.2.1, 5.0.0b1, 5.0.0b2, 5.0.0b3, 5.0.0b4, 5.0.0rc1, 5.0.0, 5.1.0, 5.2.0, 5.2.1, 5.2.2, 5.3.0, 5.4.0, 5.4.1, 5.5.0, 5.6.0, 5.7.0, 5.8.0, 6.0.0rc1, 6.0.0, 6.1.0, 6.2.0, 6.2.1, 6.3.0, 6.3.1, 6.4.0, 6.5.0)
ERROR: No matching distribution found for ipython==7.4.0 (from -r requirements.txt (line 3))

How do I get the latest version of ipython on CentOs 7? We tried compiling it by hand from a git repository but then only root has access to it but no user.

The Python-modules-latest.log and aliDoctor output are in the cernbox.

Thank you very much for your help!
Best,
Thomas