hermes update fails with "cannot import name 'file_signature' from 'utils'"

hermes update pulls new code and then dies with ImportError: cannot import name 'file_signature' from 'utils'.

Difficulty

Easy

Time

~5 min

Steps

Fixed in

v2026.9.21

Last checked

Oct 17, 2026

Verified fix: PR #112062 merged on 2026-09-15. Fixed in v2026.9.21 (first stable release containing the merge commit). Last checked 2026-10-17.

Symptom

hermes update pulls new code and then dies with ImportError: cannot import name 'file_signature' from 'utils'.

Evidence what you'll see

ImportError right after 'Fetching updates'
The update receipt is missing afterwards
The error can name another symbol from a top-level module

Cause

The updater keeps running in the old Python process and only evicted five hard-coded packages from its module cache, so a stale top-level module like utils stayed loaded.

Fix steps

0 of 2 done

Step 1Upgrade to a release that includes PR #112062, which evicts every top-level module in the project after the pull.
Step 2If an update already failed, run hermes update again; the new code is on disk and a fresh process loads it.

Your check marks stay in this browser only.

Verify the fix worked

Run hermes update and confirm it finishes without the ImportError and writes its update receipt.

Sources and credit

Summarized in our own words from these public reports. Credit goes to their authors.

Provided as is, without warranty. Try changes in a non-production environment and back up first. Security-related steps: verify against the official docs. Terms · Request removal or attribution change

Hit an error we don't cover? Submit it