This is certainly an interesting error - looks like we've come across this a couple of times before with folks on Ubuntu using virtual machines to run QIIME 2:
A couple of initial questions for you:
Are you doing a native install on Ubuntu, or using a virtual machine?
Do you have numpy installed separately in the environment you are attempting to install QIIME 2 within? And if so, what version of numpy is it? You can run conda info to list all of the current packages/versions in your environment.