Potential compatibility issue: Removing explicit `-s /bin/sh` from su command may break for users with non-POSIX login shells

[kilo-code-bot]

Issue Description

In PR #128, the su command used to drop privileges for running Homebrew commands was simplified by removing the explicit shell specification (-s /bin/sh). This change may break compatibility for users with non-POSIX login shells (e.g., fish, nushell, csh, tcsh).

Technical Details

The _brew_cmds variable contains POSIX shell syntax including:

• eval
• $() command substitution
• && logical AND
• printf with format strings

When su - ${NON_ROOT_USER} -c ${_brew_cmds} is used without -s /bin/sh, it invokes the user's login shell. If that shell is non-POSIX (like fish or nushell), the POSIX syntax in _brew_cmds will fail.

Original Code (with explicit shell)

su - ${NON_ROOT_USER} -s /bin/sh -c ${_brew_cmds}

Current Code (without explicit shell)

su - ${NON_ROOT_USER} -c ${_brew_cmds}

Recommended Fix

Restore -s /bin/sh to guarantee POSIX compliance, or use sh -c explicitly.

Context

This was flagged in the code review for PR #128 by the Kilo Code bot. The review comment can be found at: #128 (comment)

Labels: bug, compatibility, shell

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