runtime: probe user env before lifecycle hooks

[bilby91]

Summary

• Engine.Up was probing userEnvProbe only after running every lifecycle phase, so ws.probedEnv was empty during postCreateCommand (and earlier phases). Hooks that relied on PATH entries published via .bashrc / /etc/profile.d snippets — nvm-managed node, asdf, the official devcontainers-extra/pnpm feature — failed with command not found. This diverged from @devcontainers/cli, which awaits the probe promise before every lifecycle exec.
• Fix: probe before runAllLifecycle so hooks see the rc-derived env, then re-probe after so any rc edits made by the hooks themselves are reflected in subsequent Exec calls. Probe failures stay non-fatal.
• No changes to lifecycle.go / exec.go: Exec already merges ws.probedEnv, and lifecycle hooks route through Exec — updating ws.probedEnv at the right moment is sufficient.

Test plan

• go test ./... (unit) passes
• go test -tags=integration -run TestUserEnvProbe ./test/integration/ passes
• New TestUserEnvProbe_LifecycleSeesBashrcPath regression test: builds an image that drops a binary in /opt/mytool/bin and a /etc/profile.d/mytool.sh that prepends it to PATH; postCreateCommand runs command -v mytool && mytool > /tmp/lifecycle-out. Fails on the old code (Up errors because the hook can't find the binary), passes after the fix.

🤖 Generated with Claude Code

Summary by CodeRabbit

Bug Fixes

• Shell-derived environment variables are now accessible during lifecycle hook execution and are recaptured afterward to include any modifications made by the hooks.

Tests

• Added integration test for environment variable handling during lifecycle execution.

[coderabbitai]

📝 Walkthrough

Walkthrough

The PR reorders the user-environment probe in Engine.Up to execute before lifecycle hooks and again after them, ensuring lifecycle commands observe shell-derived PATH variables while subsequent operations reflect any environment changes made by those hooks. An integration test validates the visibility of probed PATH during lifecycle command execution.

Changes

Shell-environment probe and lifecycle hooks

Layer / File(s)	Summary
User-environment probe timing in lifecycle up.go	probeUserEnv is moved to execute before the lifecycle phase so lifecycle hooks see the probed shell environment, then re-runs after lifecycle to capture environment modifications made by lifecycle tools.
Lifecycle PATH visibility test test/integration/userenvprobe_test.go	Integration test TestUserEnvProbe_LifecycleSeesBashrcPath verifies that shell-derived PATH is observable during postCreateCommand execution by creating a fixture with a mytool binary and /etc/profile.d/ export, running the lifecycle, and asserting tool output.

Sequence Diagram

sequenceDiagram
  participant EngineUp
  participant probeUserEnv
  participant LifecycleHooks
  participant Exec
  
  EngineUp->>probeUserEnv: Execute before lifecycle
  probeUserEnv->>EngineUp: ws.probedEnv updated with shell PATH
  EngineUp->>LifecycleHooks: Run postCreateCommand (sees probed env)
  LifecycleHooks->>EngineUp: Lifecycle completes (may modify env)
  EngineUp->>probeUserEnv: Re-execute after lifecycle
  probeUserEnv->>EngineUp: ws.probedEnv refreshed from rc changes
  EngineUp->>Exec: Subsequent Exec calls see updated env

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Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• crunchloop/devcontainer#19: Both PRs implement the userEnvProbe capture and propagation via ws.probedEnv and change Engine.Up behavior so PATH additions from bashrc-derived files are visible during lifecycle and exec calls.

Poem

🐰 In the time of probes before and after,
The PATH leaps forth with shell-sourced laughter,
Hooks now see the tools at hand,
While tests assert this working land. ✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'runtime: probe user env before lifecycle hooks' directly and concisely describes the main change: moving user environment probe execution to occur before lifecycle hooks run.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch runtime/probe-before-lifecycle

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@up.go`:
- Around line 226-245: The current code only updates ws.probedEnv before
runAllLifecycle and after it finishes, leaving lifecycle steps (e.g.,
onCreateCommand → postCreateCommand) using a stale env; modify the lifecycle
handling so the environment is refreshed between individual lifecycle execs:
either call e.probeUserEnv(ctx, ws, ws.Config.UserEnvProbe) and update
ws.probedEnv before each lifecycle exec inside runAllLifecycle (or have
runAllLifecycle invoke a helper that re-probes between phases), ensuring errors
remain non-fatal (keep the same err==nil check) and preserving existing
semantics of e.runAllLifecycle, e.probeUserEnv, and ws.probedEnv.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: fd7272be-0d07-49c4-9735-16374fd07e8d

📥 Commits

Reviewing files that changed from the base of the PR and between e183522 and 29a35e6.

📒 Files selected for processing (2)

• test/integration/userenvprobe_test.go
• up.go