brew list --pinned
deve fazer o truque.
Estou usando o brew versão 0.9.5. A solução está listada nas páginas do manual da seguinte forma:
ls, list [--unbrewed] [--versions [--multiple]] [--pinned] [formulae] Without any arguments, list all installed formulae.
If formulae are given, list the installed files for formulae. Combined with --verbose, recursively list the contents of all subdirectories in each for- mula's keg.
If --unbrewed is passed, list all files in the Homebrew prefix not installed by Homebrew.
If --versions is passed, show the version number for installed formulae, or only the specified formulae if formulae are given. With --multiple, only show formulae with multiple versions installed.
If --pinned is passed, show the versions of pinned formulae, or only the specified (pinned) formulae if formulae are given. See also pin, unpin.