[1anZhang]

Change

mcode exec appended "Retry after the connection recovers." to every runtime failure, including Session errors that can never succeed on retry. Resuming a Session from a different directory (for example through the Python SDK's resume_thread() without cwd) printed:

mcode exec failed: The run failed: Session workspace does not match --cwd: mvs_…. Retry after the connection recovers.

It now prints:

mcode exec failed: The run failed: Session mvs_… belongs to workspace /path/to/workspace, not --cwd /path/to/project; rerun with --cwd /path/to/workspace.

• Workspace mismatch, archived Session and missing --continue target errors are marked retryable: false and say what to do next. Exit code (4) and category (runtime) are unchanged, so SDK error mapping is unaffected.

• formatTuiExecFailure and formatTuiExecResultFailure omit the retry hint for non-retryable failures (TuiExecError.retryable === false / result.error.retryable === false); retryable or unspecified failures keep it.

• Python SDK: the README (new "Resuming a Session" section, quick start) and the MCode.resume_thread / SyncMCode.resume_thread docstrings state that a resumed Session must use the cwd it was created with.

• PR labels: bug, cli.

Validation

• Checks run and results:
  • pnpm verify (full profile, darwin) on 04e800ae: passed, 17 gates. Skipped: test:windows (platform), test:release-package (needs an npm release archive).
  • New tests in packages/tui/test/unit/headless-runner.test.ts: workspace mismatch message and exit code without sending a message, archived and missing --continue messages without "Retry", and the retry hint kept only for retryable failed results.
  • Python SDK: ruff, ruff format, mypy (strict), pytest 37 passed / 3 skipped (opt-in e2e).
  • Manual: node dist/cli.js exec --session=<id> --cwd=<other dir> against a real local Session prints the new message with exit 4; the installed 0.7.1 CLI prints the old retry hint for the same input.
• Performance: not applicable.
• NOT RUN, platform limitations and live-service boundaries: Windows path display not exercised manually (comparison logic unchanged). No model call is involved in these error paths.

Publication and contribution checks

• I have permission to contribute these changes under the existing licenses applicable to the changed files/packages; imported material and its provenance are identified and existing notices are preserved.
• No credentials, account data, real user content, internal source history or private review material is included.
• Added/removed source files were reviewed before regenerating release/public-source.json; new tests are declared in test/vitest-suites.json where applicable (no files added; tests extend an existing declared file).
• Shared English/Chinese documentation and capability/verification records are updated where applicable. Mock/offline results are not described as live-service acceptance.

Maintainer handoff

Publication scope or license changes (if any): none.

Shared-source port: pending (packages/tui/src/headless/* is shared implementation).

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