Charlie Marsh ea7e0714da Fix relative MCP server spawning on macOS (#42117) ...

## Why

Rust falls back to `fork` when a macOS command combines a relative executable
path with a working directory, due to a historical `posix_spawnp` issue. This
can make local MCP server startup less reliable.

## What changed

- Spawn relative macOS MCP executables directly with `posix_spawn`, preserving
  the configured path, `argv[0]`, working directory, environment, stdio, and
  process group.
- Keep the existing launcher for `PATH` lookup and executable text files without
  a shebang.
- Use one local child wrapper for legacy and 2026-07-28 protocol framing, with
  cancellation-safe waiting and cleanup that kills and reaps dropped children.

## Testing

Add macOS regression coverage for relative scripts, argument and descriptor
preservation, launch errors, cancelled waits, and cleanup after runtime shutdown.

GitOrigin-RevId: 1cbc6b90aed6f67e0a38f551964d80496ebc4471

2026-09-01 18:53:06 +00:00

..

foreign_stdio_cwd.rs

…

mcp_2026_discovery.rs

Update rmcp to 3.1.3 (#39798)

2026-08-20 20:53:17 +00:00

mcp_2026_message_limits.rs

Complete MCP 2026 client support (#35725)

2026-07-28 06:06:58 +00:00

mcp_2026_mrtr.rs

Update rmcp to 3.1.2 (#39101)

2026-08-17 23:04:09 +00:00

mcp_2026_oauth_discovery.rs

Harden MCP OAuth callback handling (#40691)

2026-08-25 20:26:23 +00:00

mcp_2026_sse_discovery.rs

Add MCP 2026-07-28 discovery support (#35724)

2026-07-28 05:52:12 +00:00

mcp_2026_stdio_discovery.rs

Propagate custom CA settings to local MCP servers (#38040)

2026-08-11 17:24:04 +00:00

mcp_2026_stdio.rs

Fix relative MCP server spawning on macOS (#42117)

2026-09-01 18:53:06 +00:00

mcp_events.rs

Add MCP event discovery and subscriptions (#37494)

2026-08-07 19:36:52 +00:00

process_group_cleanup.rs

Fix relative MCP server spawning on macOS (#42117)

2026-09-01 18:53:06 +00:00

resources.rs

Improve sandboxing, MCP errors, and cached approvals (#41196)

2026-08-27 20:05:08 +00:00

stdio_message_limits.rs

Harden local MCP server process tree cleanup (#37366)

2026-08-07 03:34:49 +00:00

streamable_http_oauth_startup.rs

Refresh MCP HTTP helper headers after authorization failures (#41400)

2026-08-28 19:29:51 +00:00

streamable_http_oauth_store_pinning.rs

Resolve HTTP MCP bearer tokens in executor environments (#39926)

2026-08-21 12:50:15 +00:00

streamable_http_recovery.rs

…

streamable_http_remote.rs

Cache executor metadata from initialization (#40343)

2026-08-24 06:43:07 +00:00

streamable_http_test_support.rs

Use configured HTTP clients for all MCP OAuth requests (#35814)

2026-07-28 19:11:36 +00:00

streamable_http_user_agent.rs

Set a default user agent for MCP HTTP requests (#34883)

2026-07-23 06:13:12 +00:00