Amplifier fails to start after update

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#237 opened on Mar 16, 2026 2 comments 0 reactions 0 assignees View on GitHub

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Dominant language: Python
Stars: 3.1k
Forks: 261
Avg merge: 3h 28m
Merged PRs (30d): 13

Description

Ran amplifier update about 10 minutes ago. It now fails to start:

Run amplifier update to install

  • Update 7 bundles
  • Update Amplifier to latest version (dependencies have updates)

Proceed with update? [Y/n]:


✓ Update complete
  ✓ amplifier
  ✓ Bundle: amplifier
  ✓ Bundle: core
  ✓ Bundle: foundation
  ✓ Bundle: modes
  ✓ Bundle: recipes
  ✓ Bundle: shadow
  ✓ Bundle: superpowers
  Amplifier updated successfully
❯ amplifier
Traceback (most recent call last):
  File "/home/oyosefi/.local/bin/amplifier", line 4, in <module>
    from amplifier_app_cli.main import main
  File "/home/oyosefi/.local/share/uv/tools/amplifier/lib/python3.12/site-packages/amplifier_app_cli/__init__.py", line 5, in <module>
    from .main import cli
  File "/home/oyosefi/.local/share/uv/tools/amplifier/lib/python3.12/site-packages/amplifier_app_cli/main.py", line 22, in <module>
    from amplifier_core import AmplifierSession
  File "/home/oyosefi/.amplifier/cache/amplifier-core-61734c2990ff26ac/python/amplifier_core/__init__.py", line 14, in <module>
    from ._engine import RustCancellationToken as CancellationToken
ModuleNotFoundError: No module named 'amplifier_core._engine'

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First steps

Read the whole issue, then the project's contributing guide.
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Research direction

Start by reproducing the failure with amplifier after running amplifier update, then inspect the import chain through amplifier_app_cli.main, amplifier_core.__init__, and the missing _engine module. Done means the updated installation starts successfully without ModuleNotFoundError.

Written by the indexing model from the issue text.

Assessment

Tech stack: python
Domain: cli
Issue type: Bug
Difficulty: 3/5
Estimated time: 1-2 days
Activity status: Stale
Clarity: Needs clarification
Newbie friendliness: 35/100