Testing and Debugging

Debugging using PDB

It’s possible to debug any of the containers’ Python services using PDB. To do so, start up the containers as usual with:

make dev.up

This command starts each relevant container with the equivalent of the ‘–it’ option, allowing a developer to attach to the process once the process is up and running.

To attach to a container and its process, use make dev.attach.<service>. For example:

make dev.attach.lms

Set a PDB breakpoint anywhere in the code using one of the following:

breakpoint()                # Works in Python >= 3.7
import pdb;pdb.set_trace()  # Works in any version of Python

and your attached session will offer an interactive PDB prompt when the breakpoint is hit.

You may be able to detach from the container with the Ctrl-P, Ctrl-Q key sequence. If that doesn’t work, you will have either close your terminal window or stop the service with:

make dev.stop.<service>

You can bring that same service back up with:

make dev.up.<service>

Running LMS and Studio Tests

After entering a shell for the appropriate service via make lms-shell or make studio-shell, you can run any of the usual paver commands from the edx-platform testing documentation. Examples:

paver run_quality
paver test_a11y
paver test_bokchoy
paver test_js
paver test_lib
paver test_python

Tests can also be run individually. Example:

pytest openedx/core/djangoapps/user_api

Tests can also be easily run with a shortcut from the host machine, so that you maintain your command history:

./in lms pytest openedx/core/djangoapps/user_api

Connecting to Browser

If you want to see the browser being automated for JavaScript or bok-choy tests, you can connect to the container running it via VNC.


VNC connection

Firefox (Default)


Chrome (via Selenium)


On macOS, enter the VNC connection string in the address bar in Safari to connect via VNC. The VNC passwords for both browsers are randomly generated and logged at container startup, and can be found by running make vnc-passwords.

Most tests are run in Firefox by default. To use Chrome for tests that normally use Firefox instead, prefix the test command with SELENIUM_BROWSER=chrome SELENIUM_HOST=edx.devstack.chrome.

Running End-to-End Tests

To run the base set of end-to-end tests for edx-platform, run the following make target:

make e2e-tests

If you want to use some of the other testing options described in the edx-e2e-tests README, you can instead start a shell for the e2e container and run the tests manually via paver:

make e2e-shell
paver e2e_test

The browser running the tests can be seen and interacted with via VNC as described above (Firefox is used by default).