What is the primary problem Shell Guard solves?

It prevents 'ENOENT: no such file or directory' errors that occur when a script or tool cannot find a specified shell path (like /bin/bash) across different operating systems or containerized environments.

How does the fallback chain work?

If the preferred shell (Zsh) isn't found, Shell Guard automatically attempts to use Bash, then standard Sh, then /usr/bin/env, and finally falls back to a Python3 subprocess to ensure the command runs.

Do I need Babashka to use this skill?

The core implementation is optimized for Babashka, but the shell-safety logic and prompt patterns can be integrated into any environment requiring resilient shell execution.

Does this work with Nix or Flox?

Yes, Shell Guard features specific integration for Flox, allowing it to detect missing tools and automatically activate the required Nix environments before executing commands.

Shell Guard

Name: Shell Guard
Author: plurigrid

byplurigrid

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Developer Tools

Prevents shell spawn errors by implementing a robust fallback chain and environment validation for cross-platform command execution.

Shell Guard is a specialized utility designed to eliminate the common 'ENOENT' anti-pattern where Claude or other automated tools fail to locate a specific shell path. By providing a smart fallback mechanism that traverses multiple shell types—from Zsh and Bash to Python3 subprocesses—it ensures that terminal commands execute successfully regardless of whether the environment is macOS, Linux, or a Nix-managed Flox container. It includes pre-flight checks for dependencies and seamless integration with Babashka, making it an essential tool for developers building resilient automation scripts and cross-platform workflows.

Key Features

01Automated environment validation and dependency checking

02Multi-stage shell fallback chain (Zsh, Bash, Sh, Python3)

038 GitHub stars

04Configurable execution parameters including CWD, timeouts, and env variables

05Native Flox and Nix environment activation and detection

06Deterministic error recovery and automated shell path discovery

Use Cases

01Preventing script failures in CI/CD pipelines caused by hardcoded shell paths

02Standardizing shell command execution across diverse developer environments

03Automating dependency installation within isolated Flox/Nix containers

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add plurigrid/asi shell-guard

For use in Claude.ai and ChatGPT

Download Skill