[Stella Huang (StellaHuang95)]

Summary

• serialize Conda startup and explicit inventory rebuilds so persisted-selection restoration cannot append the same external prefix twice
• canonicalize resolved global and project selections by normalized environment path while preserving fast-path startup and selection identity
• add deterministic regression coverage for both persistence scopes, refresh events, no-Python updates, and cross-platform path spellings

Validation

• npm run lint
• npm run compile-tests
• npm run unittest (3,300 passing, 9 pending)
• npm run compile
• smoke tests (30 passing, 1 pending)
• baseline VS Code E2E tests (4 passing)
• manual two-process restart in ordinary VS Code 1.142.0 using Conda 26.9.3 and an isolated, unregistered external Python 3.11.17 prefix:
  • target absent from initial discovery, then selected and persisted as one underlying object
  • same profile/workspace reopened with startup getEnvironment() and explicit refresh triggered concurrently; one underlying object remained and selection was restored
  • real environment picker rendered and was cancelled without changing selection
  • subsequent explicit refresh retained one object and the same selected prefix
  • selected interpreter executed a probe successfully with the expected sys.prefix and executable

Fixes #1870

[Copilot]

🟢 Approval recommended

The focused changes address the reported race with deterministic regression coverage and no identified blocking issues.

No open issues 🎉

What changed in this PR

Fixes duplicate Conda environments after restart by coordinating inventory rebuilds and reusing canonical environment objects for persisted selections.

Changes:

• Serializes startup discovery and explicit refreshes.
• Deduplicates resolved selections by normalized environment path.
• Adds deterministic regression tests for both persistence scopes, refresh events, and path variants.

File	Description
src/​test/​managers/​conda/​condaEnvManager.refreshRace.unit.test.ts	Tests concurrent restoration, refresh ordering, and selection identity.
src/​managers/​conda/​condaEnvManager.ts	Queues inventory rebuilds and canonicalizes resolved environments.

_{Review effort: Balanced}

[Rich Chiodo (rchiodo)]

🔒 Automated review in progress — Rich Chiodo (@rchiodo) is auto-reviewing this PR.

[Rich Chiodo (rchiodo)]

Approved via Review Center.

[Bill Schnurr (bschnurr)]

Approved via Review Center.

[Heejae Chang (heejaechang)]

Approved via Review Center.