Enforce target-aware working directories by MGudgin · Pull Request #1253 · microsoft/mxc

Gudge (MGudgin) · 2026-09-23T22:06:24Z

📖 Description

This PR fixes process.cwd validation across MXC execution surfaces.

Current JSON contracts and typed SDK requests now require a path that is
absolute for the target backend and lifecycle surface. Released v0.6-v0.8
relative-path compatibility is preserved for ordinary backends, while WSLc
continues to reject any explicit value it cannot map faithfully.

Resolves #902

Details

Carries cwd compatibility semantics from exact contract adapters into the
normalized execution request.
Validates Windows, POSIX, and WSLc one-shot/state-aware path forms without
depending on the compilation host.
Rejects invalid cwd before backend selection, host DACL changes, dry-run
success, or state-aware backend dispatch.
Separates strict WSLc cwd mapping from legacy filesystem-mount mapping.
Preserves stable public error classifications for policy and availability
failures.
Updates canonical, backend, generated-contract, and Rust/Node/.NET SDK
documentation.
Adds adapter, normalization, validator, dispatcher, backend, regression, and
E2E coverage.

Tests

cargo fmt --all -- --check
Focused tests for wxc_common, wslc_common, mxc_engine,
process_container_common, windows_sandbox_lifecycle,
mxc_config_contract, and nanvix_runner
cargo clippy --workspace --all-targets -- -D warnings
Node SDK build and unit tests
.NET SDK build
Exact-contract codegen drift check
Working-directory E2E tests
Issue [Cross-backend] process.cwd is silently discarded or resolved against host state #902 regression for strict rejection and v0.8 compatibility
Three-round iterative adversarial review converged with all findings closed

Microsoft Reviewers: Open in CodeFlow

azure-pipelines · 2026-09-23T22:06:34Z

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Copilot

Copilot review overview

🟡 Changes recommended

Legacy WSLc preflight and executor-backed Node typed requests do not consistently enforce the intended strict semantics.

Get a fresh assessment by requesting another Copilot review.

Review effort: Balanced
Findings: 2 · 1

Open (3)

Executor-backed spawn path lacks strict cwd validation · New
Legacy cwd bypass incorrectly applies to WSLc · New
Document unsupported UNC and device working-directory paths · New

What changed in this PR

This PR introduces target-aware process.cwd validation across contracts, backends, execution surfaces, and SDKs.

Changes:

Adds version- and backend-aware working-directory validation.
Preserves legacy contract compatibility while hardening WSLc mapping.
Updates SDKs, diagnostics, documentation, and regression coverage.

File	Description
`tests/regression_tests/test_cases/Invoke-Issue902-RelativeWorkingDirectory.ps1`	Tests strict and v0.8 behavior.
`src/testing/wxc_e2e_tests/tests/e2e_working_directory.rs`	Adds cross-platform cwd E2E tests.
`src/core/wxc_common/src/working_directory.rs`	Implements target-aware validation.
`src/core/wxc_common/src/validator.rs`	Integrates one-shot and exec validation.
`src/core/wxc_common/src/state_aware_dispatch.rs`	Tests pre-dispatch rejection.
`src/core/wxc_common/src/script_runner.rs`	Preserves public error classifications.
`src/core/wxc_common/src/policy_identity.rs`	Excludes compatibility metadata from identity.
`src/core/wxc_common/src/models.rs`	Adds cwd compatibility and style models.
`src/core/wxc_common/src/lib.rs`	Exports shared path helpers.
`src/core/wxc_common/src/config_parser.rs`	Validates cwd during normalization.
`src/core/wxc_common/src/config_deserialize.rs`	Exposes diagnostic escaping.
`src/core/wxc_common/src/config_contract_adapters/v0_9/state_aware.rs`	Selects strict state-aware semantics.
`src/core/wxc_common/src/config_contract_adapters/v0_9/state_aware_tests/common.rs`	Tests strict adapter output.
`src/core/wxc_common/src/config_contract_adapters/v0_9/one_shot.rs`	Selects strict one-shot semantics.
`src/core/wxc_common/src/config_contract_adapters/v0_9/one_shot_tests/common.rs`	Tests strict adapter output.
`src/core/wxc_common/src/config_contract_adapters/v0_8.rs`	Selects legacy cwd compatibility.
`src/core/wxc_common/src/config_contract_adapters/v0_7.rs`	Selects legacy cwd compatibility.
`src/core/wxc_common/src/config_contract_adapters/v0_6.rs`	Selects legacy cwd compatibility.
`src/core/wxc_common/src/config_contract_adapters/dev/state_aware.rs`	Selects strict development semantics.
`src/core/wxc_common/src/config_contract_adapters/dev/state_aware_tests/common.rs`	Tests development adapter output.
`src/core/wxc_common/src/config_contract_adapters/dev/one_shot.rs`	Selects strict development semantics.
`src/core/wxc_common/src/config_contract_adapters/dev/one_shot_tests/common.rs`	Tests development adapter output.
`src/core/wxc_common/src/common_request_ir.rs`	Carries cwd compatibility metadata.
`src/core/mxc-sdk/README.md`	Documents Rust SDK cwd rules.
`src/core/mxc_engine/src/run.rs`	Validates before runner resolution.
`src/core/mxc_engine/src/policy/exact/mod.rs`	Makes typed requests strict.
`src/core/mxc_engine/src/policy.rs`	Documents and tests typed requests.
`src/core/mxc_engine/src/dispatch.rs`	Validates streaming requests early.
`src/core/mxc_config_contract/src/dev/stable.rs`	Documents development contract semantics.
`src/backends/wslc/common/src/wsl_container_runner.rs`	Rejects or maps one-shot cwd.
`src/backends/wslc/common/src/policy_mapping.rs`	Separates strict cwd mapping.
`src/backends/windows_sandbox/lifecycle/src/error.rs`	Corrects unavailable-backend classification.
`src/backends/seatbelt/common/src/seatbelt_runner.rs`	Preserves legacy relative behavior.
`src/backends/nanvix/runner/src/lib.rs`	Corrects test containment context.
`sdk/node/tests/integration/wslc-e2e.test.ts`	Verifies WSLc cwd mapping.
`sdk/node/tests/integration/common.test.ts`	Tests buffered Node rejection.
`sdk/node/src/types.ts`	Documents Node cwd requirements.
`sdk/node/src/sandbox.ts`	Updates Node API documentation.
`sdk/node/src/generated/v0_10_0_alpha/wire.ts`	Regenerates wire documentation.
`sdk/node/README.md`	Documents Node compatibility rules.
`sdk/dotnet/README.md`	Documents .NET cwd rules.
`sdk/dotnet/Microsoft.Mxc.Sdk/StateAwareTypes.cs`	Documents state-aware cwd forms.
`sdk/dotnet/Microsoft.Mxc.Sdk/SandboxRequest.cs`	Documents one-shot cwd forms.
`schemas/dev/mxc-config.schema.0.10.0-alpha.json`	Updates generated schema description.
`docs/wsl/wsl-container-getting-started.md`	Documents WSLc path mapping.
`docs/windows-sandbox/windows-sandbox.md`	Documents Windows Sandbox cwd rules.
`docs/state-aware-lifecycle/mxc-state-aware-sandbox-api.md`	Documents pre-dispatch validation.
`docs/seatbelt/seatbelt-backend.md`	Documents Seatbelt compatibility.
`docs/schema.md`	Defines canonical cwd semantics.
`docs/lxc-support/lxc-backend.md`	Documents LXC cwd behavior.
`docs/isolation-session/state-aware-rust.md`	Documents IsolationSession exec rules.
`docs/isolation-session/oneshot.md`	Documents IsolationSession one-shot rules.
`docs/bwrap-support/bubblewrap-backend.md`	Documents Bubblewrap cwd behavior.
`.github/copilot-instructions.md`	Adds repository cwd invariants.

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Copilot

Copilot review overview

🟡 Changes recommended

Legacy WSLc requests bypass pre-selection validation, and unresolved state-aware targets can receive incorrect error classifications.

Get a fresh assessment by requesting another Copilot review.

Review effort: Balanced
Findings: 3 · 1

Open (4)

Validate cwd only after resolving a known sandbox target · New
Legacy cwd bypass incorrectly applies to WSLc
Executor-backed spawn path lacks strict cwd validation
Document unsupported UNC and device working-directory paths

Copilot

Copilot review overview

🟡 Changes recommended

The IsolationSession one-shot documentation describes a broader Windows path form than the validator accepts.

Get a fresh assessment by requesting another Copilot review.

Review effort: Balanced
Findings: 1

Open (1)

Document supported rooted Windows path format · New

Resolved since last review (4)

Validate cwd only after resolving a known sandbox target
Legacy cwd bypass incorrectly applies to WSLc
Executor-backed spawn path lacks strict cwd validation
Document unsupported UNC and device working-directory paths

Copilot

Copilot review overview

🟡 Changes recommended

WSLc parent-directory components are mapped with POSIX rather than rooted Windows semantics, potentially selecting the wrong container directory.

Get a fresh assessment by requesting another Copilot review.

Review effort: Balanced
Findings: 1

Open (1)

Preserve Windows root-clamping semantics for parent path components · New

Resolved since last review (1)

Document supported rooted Windows path format

Copilot

Copilot review overview

🔵 Needs a closer look

Cross-platform path semantics, compatibility behavior, generated contracts, and multiple SDK surfaces warrant final human validation.

Review effort: Balanced
Findings: None

Resolved since last review (1)

Preserve Windows root-clamping semantics for parent path components

Jeff Whiteside (jsidewhite)

🕐

Copilot

Copilot review overview

🟡 Changes recommended

The Bubblewrap guide and canonical schema documentation give contradictory omitted-cwd behavior.

Get a fresh assessment by requesting another Copilot review.

Review effort: Balanced
Findings: 1

Open (1)

Align cwd documentation with Bubblewrap's omitted-cwd behavior · New

Jeff Whiteside (jsidewhite) · 2026-09-24T00:03:16Z

mapping and its table-driven tests.

nit: prefer to keep this file hand-authored (though it, admittedly, was not hand authored)

Refers to: .github/copilot-instructions.md:78 in a39273e. [](commit_id = a39273e, deletion_comment = False)

This PR fixes #902 by validating process.cwd against the resolved backend and lifecycle surface, preserving released compatibility where intended, and rejecting values that cannot be represented faithfully. Details * Carry cwd compatibility semantics from exact contract adapters. * Require target-absolute paths for current JSON and typed SDK requests. * Unify WSLc one-shot and state-aware exec on in-container POSIX paths. * Keep Windows host-path mapping limited to WSLc filesystem grants. * Validate before backend selection or host policy changes. * Map one-shot policy and availability errors to stable public error codes. * Correct Bubblewrap's documented omitted-cwd behavior. * Document backend conventions and public Rust, Node, and .NET SDK behavior. * Add regression, E2E, backend-style, and generated-contract coverage. Tests * `cargo fmt --all -- --check` * `cargo check --workspace --all-targets` * Full `wxc_common` and `wslc_common` unit suites * Targeted Clippy for `wxc_common` and `wslc_common` with warnings denied * Node SDK build, unit tests, and changed WSLC E2E type-check * .NET SDK tests: 323 passed, 27 host-dependent tests skipped * Exact-contract codegen drift and repository config validation * Working-directory E2E tests and the #902 regression Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 65717fe2-44ac-4aa4-9629-24ae8c7d1f5e Generated-with: gpt-5.6-sol

Copilot

Copilot review overview

🔵 Needs a closer look

The cross-platform parser, engine, backend, and SDK changes require final human validation despite extensive coverage.

Review effort: Balanced
Findings: 1

Open (1)

Clarify whitespace validation behavior for paths · New

Resolved since last review (1)

Align cwd documentation with Bubblewrap's omitted-cwd behavior

+Relative, Windows, whitespace-padded, and interior-NUL cwd values are rejected
+before WSLC startup rather than being silently ignored. If `process.cwd` is
+omitted, the workload starts at the container root (`/`). WSLc applies this
+strict rule in every contract version.


Gudge (MGudgin) requested review from a team and a balanced review from Copilot September 23, 2026 22:06

Gudge (MGudgin) requested a review from a team as a code owner September 23, 2026 22:06

microsoft-github-policy-service Bot added the Copilot-Instructions PR modifies Copilot instruction files (.github/copilot-instructions.md or .github/instructions/) label Sep 23, 2026

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Gudge (MGudgin) force-pushed the user/gudge/process_cwd_fix branch from 2515905 to 3bc3eed Compare September 23, 2026 22:13

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📖 Description

Tests

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Gudge (MGudgin) commented Sep 23, 2026 •

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