**Superenv** is an attempt to improve build-reliability and end-build-quality. It is:
* The user’s `PATH` is ignored. Thus, only tools we authorize can be used during builds<sup>[1](#_1)</sup>.
*`PATH` is reconstructed. For example: `/usr/local/Library/$ENV/4.3:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin`.
*`/usr/local/Library/$ENV/4.3` (`superbin`<sup>[2](#_2)</sup>) contains wrapper-scripts for `cc`, etc.)
* We unset all build-related `ENV` variables.
* Build systems now pick their preferred compilers from `superbin`.
*`superbin` scripts are smart. They forcibly insert all include-paths and library-paths that Homebrew formulae need to compile, as well as remove flags that break builds.
## Rationale & Benefits
Because we are working with a practically virgin environment, we are essentially giving build-systems the kind of environments that the developers are using to build with. This makes them more reliable. By stepping into the toolchain between the build-system and the compiler, we have complete control over the toolchain. We can prevent a good deal of breakage, and it ensures that Homebrew uses the same executables that the compiler sees (and not those bundled with the system).
