Information

• Qiskit Terra version:

pip freeze | grep qiskit
qiskit-aer==0.2.1
-e git+git@github.com:dongreenberg/aqua.git@f2a3a9295df5eb014bdd4873a838afd810884434#egg=qiskit_aqua
-e git+git@github.com:dongreenberg/qiskit-chemistry.git@1aef6b6adc4b617ec5423b77e8fdbf4836302d13#egg=qiskit_chemistry
qiskit-ibmq-provider==0.2.2
-e git+git@github.com:Qiskit/qiskit-ignis.git@b2d46124f19b937b322eeae63eb3461bcb761745#egg=qiskit_ignis
# Editable install with no version control (qiskit-terra==0.9.0)
-e /-----/lib/python3.6/site-packages/qiskit_terra-0.9.0-py3.6-macosx-10.7-x86_64.egg

• Python version:
  3.6
• Operating system:
  OSX

What is the current behavior?

I just updated my local Aqua and Terra to master, and received the following error when trying to run an Aqua test, or just import BasicAer from the terminal:

    from qiskit import BasicAer
E   ImportError: cannot import name 'BasicAer'

Note that all basicaer unittests in the terra repo pass.

I've seen this error hundreds of times, both on my own system and collaborators'. The only solution is:

1. Try uninstalling and reinstalling qiskit packages indiscriminately in varying orders.
2. If 1) does not succeed, try nuking my installs and reinstall from scratch.

This process is very time consuming.

Often when I am working on Qiskit code directly, many classes of bugs raise the error above rather than surface the actual syntax or logic error to me directly. This makes debugging very difficult and time consuming.

I cannot rely on the Qiskit metapackage pip install to work these things out for me because I am writing code to contribute to Qiskit.

Steps to reproduce the problem

Update Qiskit installations.

What is the expected behavior?

Surface module not found errors only when modules are not installed. If there are installation issues, surface them during installation, rather than showing installation success.

Suggested solutions