Python3 + Virtualenv - Can't pip install tensorflow

I’m using debian (in crostini), with nix package manager, home manager, and trying to use virtualenv + python3. With the nix installed virtualenv and python3 tensorflow won’t install complaining about the platform. I’ve tried with python3, python37 and python36.

cat /etc/issue
Debian GNU/Linux 9 \n \l

Couldn’t get any version of tensorflow to install, it’s the only thing in requirements.txt.

pip3 install -r requirements.txt                                                                                                                                                        
Collecting tensorflow (from -r requirements.txt (line 1))                                                                                                                                                   
  ERROR: Could not find a version that satisfies the requirement tensorflow (from -r requirements.txt (line 1)) (from versions: none)                                                                       
ERROR: No matching distribution found for tensorflow (from -r requirements.txt (line 1))

A common issue with the same error from searching was installing a 32 bit version instead of 64. Didn’t seem to be what I’m running into.

python3 -c 'import struct;print( 8 * struct.calcsize("P"))'