With Kdevelop 4 I had to install either kdevelop-python2 or kdevelop-python since they were not compatible. Since the release of kdevelop 5 the kdevelop-python2 package has disappeared from the Arch repo, so I thought that finally KDevelop is supporting python2 and 3 together without the need of installing and removing packages.

Apparently it is not true since I get an error message that tells me that only python 3 debug is supported. How can I debug python 2 applications?

Sorry, Python 2 support is gone. I don't have the resources to maintain both. Use KDevelop 4 if you really need Python 2 support.

Too bad, but I understand. I'll try to compile kdevelop 4 so.