See https://firefox-ci-tc.services.mozilla.com/tasks/CxpB-_fVQY-k9JpAlUaVFA
and log: https://firefoxci.taskcluster-artifacts.net/CxpB-_fVQY-k9JpAlUaVFA/1/public/logs/live_backing.log

[task 2020-07-28T03:28:28.841Z] 03:28:28     INFO - [mozharness: 2020-07-28 03:28:28.841748Z] Running create-virtualenv step.
[task 2020-07-28T03:28:28.841Z] 03:28:28     INFO - Running main action method: create_virtualenv
[task 2020-07-28T03:28:28.841Z] 03:28:28     INFO - Creating virtualenv /builds/worker/workspace/venv
[task 2020-07-28T03:28:28.841Z] 03:28:28    FATAL - Can't find the virtualenv module
[task 2020-07-28T03:28:28.841Z] 03:28:28    FATAL - Running post_fatal callback...
[task 2020-07-28T03:28:28.841Z] 03:28:28    FATAL - Exiting -1
[task 2020-07-28T03:28:28.841Z] 03:28:28     INFO - [mozharness: 2020-07-28 03:28:28.841958Z] Finished create-virtualenv step (failed)

This is blocking releases.

Can you please rpvide the command that resulted in the failure
I'll try and fix this asap

The task is defined at https://hg.mozilla.org/releases/mozilla-beta/file/FIREFOX_80_0b1_BUILD1/taskcluster/ci/release-generate-checksums/kind.yml
It runs mozharness/scripts/release/generate-checksums.py.

I think this might fix the issue the virtualenv module not found
Can you please verify it because I'm not able to reproduce the error on my system.

Thanks for your contribution! I ran your change against our automation via a staging release task, via ./mach try scriptworker generate-checksums --release-type beta.

before: https://treeherder.mozilla.org/#/jobs?repo=try&revision=afb775679d7701fa7af808155f1be23102adcbeb&selectedTaskRun=PHowfHfAQl-0U6Rx4yJUTA.0
after: https://treeherder.mozilla.org/#/jobs?repo=try&revision=69055b5dcb1c80b0948bd55cf2bd4fa9c89d1fa2

Currently waiting for results to show up to ensure it fixes the issue.

https://hg.mozilla.org/releases/mozilla-beta/rev/2258ad2194cb

https://hg.mozilla.org/mozilla-central/rev/d9e59bcc3793

This is hitting ESR78 now.
https://treeherder.mozilla.org/logviewer?job_id=330191198&repo=mozilla-esr78&lineNumber=283

https://hg.mozilla.org/releases/mozilla-esr78/rev/f35972ee2800dd61e7994a3340b721df8887f8bd

Comment on attachment 9166609 [details]
Bug 1655666: [mozharness] Always set abs_src_path if GECKO_PATH is in the environment;

Needed to unblock the 78.8esr release, approving retroactively.