Non-PTY bash commands now spawn via posix_spawn on macOS and modern Linux, avoiding a daemon fork and the memory copy it incurs, while keeping sandboxing, session isolation, and process-tree cleanup unchanged.
Older libcs that lack the required posix_spawn extensions fall back to the previous fork-based path; the backend and fallback attempt counts are surfaced in health/status metrics.
Adds zero-fork, grandchild-kill, fd-isolation, signal-mask, and spawn-latency tests; native-only assertions skip when the local glibc predates the required capability and fail on newer libcs if the backend is unexpectedly missing.
Confidence Score: 5/5
The changes since the previous review appear safe to merge.
Summary
Non-PTY Bash commands use posix_spawn on supported hosts, with the existing fork path available when required capabilities are missing.
Non-PTY Bash commands use posix_spawn when the host supports it.
Health and status show which Bash spawn path is active.
Diagram
%%{init: {'theme': 'neutral'}}%%
flowchart TD
A[Non-PTY Bash command] --> B{Native capabilities available?}
B -->|Yes| C[posix_spawn]
B -->|No| D[Existing fork path]
C --> E[Track child and process group]
D --> E
E --> F[Observe exit or stop descendants]
