Windows runx skill/harness cannot spawn registry skills whose runner command is /usr/bin/env

[fengyangxxx]

Summary

During a public registry smoke matrix on Windows with runx-cli 0.6.13, registry packages installed and inspected successfully, but direct skill or harness runs failed when the package runner command was /usr/bin/env.

Environment

• Host OS: Windows
• CLI: runx-cli 0.6.13
• Registry: https://api.runx.ai
• Packages observed:
  • runx/dependency-cve-audit@sha-e11c90bbeb16
  • ryde-play/dep-upgrade-plan@sha-7a1f34b0

Reproduction

runx skill runx/dependency-cve-audit@sha-e11c90bbeb16 --registry https://api.runx.ai -i target_name=OWASP_NodeGoat -i target_repo=https://github.com/OWASP/NodeGoat -i target_ref=c5cb68a7084e4ae7dcc60e6a98768720a81841e8 -i package_lock_url=https://raw.githubusercontent.com/OWASP/NodeGoat/c5cb68a7084e4ae7dcc60e6a98768720a81841e8/package-lock.json -i scan_scope=direct -i include_dev=false -j

runx harness <installed dep-upgrade-plan SKILL.md> --json

Observed

Both failed while spawning /usr/bin/env on Windows with os error 3 / path not found.

Expected

Either registry skills using /usr/bin/env should run through a Windows-compatible shim, or the CLI should return a clearer platform compatibility diagnostic before attempting to spawn a POSIX-only runner.