`uv sync` fails instantly with `context canceled` during plugin installation

[ebertti]

Bug Report: uv sync fails instantly with context canceled during plugin installation

Self Checks

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Versions

1. dify-plugin-daemon Version: 0.5.4-local (langgenius/dify-plugin-daemon:0.5.4-local)
2. dify-api Version: 1.13.2
3. uv Version (inside container): 0.10.10
4. Python Version (inside container): 3.12.3
5. Deployment: Docker (via Coolify)

Describe the bug

When installing a plugin (e.g., langgenius/gemini:0.7.19) from the marketplace, the plugin daemon fails to initialize the Python environment. The uv sync command fails instantly (~0.4ms) with context canceled error, meaning the command never actually starts executing.

However, running uv sync manually inside the container in the same plugin directory succeeds without issues (completes in ~8 seconds, installs 70 packages).

Key observations

1. The virtual environment is always marked as "invalid" and deleted before the install attempt.
2. The !BADKEY in the log suggests a Go slog formatting bug in environment_python.go:27.
3. The error occurs in 0.4ms — the Go context is already canceled before exec.Command starts.
4. Network is fine: curl -s https://pypi.org/simple/dify-plugin/ works from inside the container.
5. Disk space is fine: 337GB available on /app/storage.
6. Memory is fine: container uses ~212MB of 31GB, no OOM kills in dmesg.
7. Older plugin version works: langgenius/gemini:0.7.0 (which already had a valid .venv) loads correctly after restart.

To Reproduce

1. Deploy Dify 1.13.2 with dify-plugin-daemon:0.5.4-local
2. Try installing langgenius/gemini:0.7.19 from the marketplace
3. Plugin fails with: failed to launch plugin: failed to install dependencies: failed to start command: context canceled

Relevant Logs

INFO  dify-plugin-daemon logger.go:15 local runtime starting plugin=langgenius/gemini:0.7.19@8eada8d6c655509364283527db67e47a4603021cda289f571af10e217459cf49
INFO  dify-plugin-daemon launcher_local.go:78 acquiring distributed init lock plugin=langgenius/gemini:0.7.19@8eada8d6c655509364283527db67e47a4603021cda289f571af10e217459cf49 expire=15m0s
WARN  dify-plugin-daemon environment_python.go:27 virtual environment for %s is invalid; deleting and recreating !BADKEY=langgenius/gemini:0.7.19
WARN  dify-plugin-daemon setup_python_environment.go:351 deleting existing Python virtual environment plugin=langgenius/gemini:0.7.19 path=/app/storage/cwd/langgenius/gemini-0.7.19@8eada8d6c655509364283527db67e47a4603021cda289f571af10e217459cf49/.venv
INFO  dify-plugin-daemon setup_python_environment.go:385 detected dependency file plugin=langgenius/gemini:0.7.19 file=pyproject.toml
INFO  dify-plugin-daemon setup_python_environment.go:157 installing plugin dependencies plugin=langgenius/gemini:0.7.19 method="uv sync" file=pyproject.toml
ERROR dify-plugin-daemon logger.go:24 local runtime start failed plugin=langgenius/gemini:0.7.19@8eada8d6c655509364283527db67e47a4603021cda289f571af10e217459cf49 error="failed to install dependencies: failed to start command: context canceled\nfailed to init environment"
INFO  dify-plugin-daemon launcher_local.go:93 released distributed init lock plugin=langgenius/gemini:0.7.19@8eada8d6c655509364283527db67e47a4603021cda289f571af10e217459cf49

Note: The time between "installing plugin dependencies" and "ERROR" is only 0.4ms (15:03:21.557979195Z → 15:03:21.5584203Z), confirming the command never actually starts.

Manual uv sync works

$ docker exec -w /app/storage/cwd/langgenius/gemini-0.7.19@8eada8d6c655509364283527db67e47a4603021cda289f571af10e217459cf49 \
    plugin_daemon-container uv sync 2>&1
Resolved 73 packages in 46ms
...
Installed 70 packages in 3.11s

Workaround

Running uv sync manually inside the container in the plugin directory, then restarting the plugin daemon, allows the plugin to load (since the .venv is already valid). However, the daemon still fails to install new plugins automatically.

Expected behavior

Plugin should be installed and initialized automatically without requiring manual intervention.

Possibly related issues

• Re-Opened: Can’t install plugins from either local packages or the marketplace. #649 (marketplace install fails with --offline flag)
• Can’t install plugins from either local packages or the marketplace. #646
• failed to launch plugin: failed to install dependencies: failed to install dependencies dify#29589 (similar symptoms but signal: killed)

[dosubot]

This is a known bug that's been reported in multiple issues. The root cause is that the HTTP request context is incorrectly reused for background plugin installation tasks. When the HTTP handler returns after sending a task ID, the request context is canceled, which immediately cancels the uv sync command before it even starts—explaining the 0.4ms timing you observed.

However, you're on 0.5.4-local, which should include the context cancellation fix from PR #596. The more likely culprit for your specific version is a second bug introduced in PRs #624 and #644: marketplace plugin installs now incorrectly use uv --offline mode, blocking PyPI dependency downloads entirely. This was confirmed in issue #649.

Recommended workaround: Downgrade to 0.5.3-local (predates both bugs):

plugin_daemon:
    image: langgenius/dify-plugin-daemon:0.5.3-local

Then restart: docker-compose down && docker-compose up -d

There's an open PR #651 to revert the problematic offline mode changes.

You also correctly identified the !BADKEY logging bug—it's a simple slog formatting error in environment_python.go:27 where printf-style formatting was used instead of structured key-value pairs.

To reply, just mention @dosu.

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[ebertti]

Confirmed: Downgrade to 0.5.3-local fixes the issue

I can confirm that downgrading from 0.5.4-local to 0.5.3-local completely resolves the plugin installation issue.

Before (0.5.4-local):

• Plugin installation failed instantly with context canceled error
• uv sync never actually executed (failed in 0.4ms)
• Manual uv sync worked fine in the container

After (0.5.3-local):

• Plugin langgenius/gemini:0.7.19 installed successfully from marketplace
• No more context canceled errors
• Plugin loads and works as expected

Configuration change:

plugin_daemon:
  image: 'langgenius/dify-plugin-daemon:0.5.3-local'  # Changed from 0.5.4-local

This confirms that the issue was indeed introduced in the 0.5.4 release with the --offline mode changes from PRs #624/#644, as mentioned in the issue description.

Thanks for the quick diagnosis and workaround! Looking forward to PR #651 being merged so we can upgrade again.