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Crow CI

Backend: Local

Local backend configuration variables for agents.

BACKEND_LOCAL_TEMP_DIR

Section titled “BACKEND_LOCAL_TEMP_DIR”
  • Name: CROW_BACKEND_LOCAL_TEMP_DIR
  • Description: Directory in which pipelines are executed
  • Default: $TMPDIR

Each workflow gets its own directory below this one, and steps run with $TMPDIR pointing inside it rather than at the shared temp directory. On Windows, TMP and TEMP point there as well.

BACKEND_LOCAL_SANDBOX_LEVEL

Section titled “BACKEND_LOCAL_SANDBOX_LEVEL”
  • Name: CROW_BACKEND_LOCAL_SANDBOX_LEVEL
  • Description: Process isolation level on macOS, one of none, standard or strict
  • Default: standard

The standard macOS sandbox also permits the agent account’s system temporary directory and build caches, even when the agent starts with custom HOME or TMPDIR values. This lets Apple toolchain launchers such as xcrun and account-based tool installations write their caches while keeping other workflows’ directories isolated.

Implemented with the macOS sandbox-exec utility, and a no-op on Linux and Windows. See macOS Sandbox Security Levels for what each level allows.

BACKEND_LOCAL_USE_HOST_HOME

Section titled “BACKEND_LOCAL_USE_HOST_HOME”
  • Name: CROW_BACKEND_LOCAL_USE_HOST_HOME
  • Description: Run steps with the agent account’s own home instead of a per-workflow one
  • Default: false

Needed by tools that resolve the home directory from the account rather than from $HOME, such as Xcode reading provisioning profiles and writing DerivedData. Trades home isolation between workflows for compatibility with them.

macOS process cleanup

Section titled “macOS process cleanup”

The macOS local backend stops each step’s process group on cancellation and stops remaining workflow process groups before deleting the workspace. It also assigns an inherited process marker to each step so detached tools such as sccache can be found after their launcher exits. Cleanup waits for processes to exit and reports errors before removing workflow directories. Concurrent workflows have independent markers and process groups.

This is cooperative cleanup, not a security boundary. Processes that detach and discard their marker, change user, or hide their environment from the agent may escape discovery. Use VM or container isolation for untrusted jobs.

Compiler-cache integrations should additionally isolate their daemon per build and stop it on exit. Crow’s cleanup handles leftovers; it cannot make a shared daemon use two different macOS workflow sandboxes at the same time. The sccache plugin’s native sccache-run wrapper provides this isolation.