npm-force-install-can-overwrite-system-binaries
Installing ast-grep via npm install -g --force silently overwrote /usr/bin/sg — the system newgrp binary — replacing it with ast-grep’s sg shortcut. Always verify system binary integrity after any global npm install with --force: check which sg && ls -la /usr/bin/sg and restore with ln -sf /usr/bin/newgrp /usr/bin/sg if overwritten. Install ast-grep via its dedicated binary (ast-grep CLI) rather than relying on the sg alias to avoid the collision.