Homebrew cask launcher asks for AZ_PYTHON when the Homebrew prefix is a symlink #34199

Describe the bug

With the new Homebrew cask (brew install --cask azure-cli, 2.91.0), az fails on a Mac where the Homebrew prefix is a symlink (here /opt/homebrew -> /private/.bulk/opt/homebrew, which itself resolves to another volume):

Error: AZ_PYTHON not set.
For offline/tarball installs, set AZ_PYTHON to a Python 3.14 path.

Cause: scripts/release/standalone/templates/az_launcher.sh.in resolves its own path with cd -P (physical), then compares the result against literal prefixes:

if [[ "$SCRIPT_PATH" == /opt/homebrew/Caskroom/* ]] || \
    [[ "$SCRIPT_PATH" == /usr/local/Caskroom/* ]] || \
    [[ "$SCRIPT_PATH" == /home/linuxbrew/.linuxbrew/Caskroom/* ]]; then

bash -x shows the resolved path is /Volumes/Data/.bulk/opt/homebrew/Caskroom/azure-cli/2.91.0/bin/../libexec/bin/az, so INSTALLER=TARBALL and the launcher demands AZ_PYTHON, even though it is a cask install and python@3.14 is installed. The same happens with any custom Homebrew prefix.

To reproduce

1. Make the Homebrew prefix a symlink to another location (for example, a prefix relocated to a second volume).
2. brew install --cask azure-cli
3. az version

Expected behavior

The cask install is detected and uses Homebrew's python@3.14, with no AZ_PYTHON needed.

Suggestions

• Detect a cask install by pattern rather than literal prefix, for example */Caskroom/azure-cli/*. Or compare against the physical path of $HOMEBREW_PREFIX, or brew --prefix.
• Minor: the first candidate, opt/python@3.14/libexec/bin/python3, doesn't exist in Homebrew's python@3.14 (its libexec/bin has python, not python3). Detection only works because of the bin/python3.14 fallback.

Workaround

export AZ_PYTHON="$HOMEBREW_PREFIX/opt/python@3.14/bin/python3.14"

Environment

• azure-cli 2.91.0, Homebrew cask (Homebrew 7.0.8), macOS 27 on Apple silicon
• Homebrew prefix: /opt/homebrew, a symlink to /private/.bulk/opt/homebrew