gsutil: No module named google_compute_engine

While trying to run gsutil ls on a Compute Engine VM, I received a stack trace like this:

Traceback (most recent call last):
  ...
ImportError: No module named google_compute_engine

It turns out that gsutil doesn't like Python installed from Linuxbrew.  It really wants to use the system Python.  The following works fine:

env CLOUDSDK_PYTHON=/usr/bin/python gsutil ls ...

Easy enough to fix.  Nobody else had documented trouble with this configuration so here you go Internet.