Is there any way to force homebrew to install all of its formulas keg-only, i.e. without system-wide side effects? Could something similar be accomplished simply by running brew unlink <name> after every formula?
The reason I'm asking this is I'd like to have a secondary installation of homebrew that acts like a sort of installer for the dependencies of a hard-to-build scientific program, compiling and installing those dependencies with some degree of isolation from the rest of my system.
You can create a separate Homebrew installation somewhere other than
/usr/local. But you don't need to install everything keg-only to do that.