diff options
Diffstat (limited to 'share/doc/homebrew/Homebrew-0.9.3.md')
| -rw-r--r-- | share/doc/homebrew/Homebrew-0.9.3.md | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/share/doc/homebrew/Homebrew-0.9.3.md b/share/doc/homebrew/Homebrew-0.9.3.md new file mode 100644 index 000000000..a6d32d2b0 --- /dev/null +++ b/share/doc/homebrew/Homebrew-0.9.3.md @@ -0,0 +1,34 @@ +# Homebrew 0.9.3 +## What is Superenv? + +**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). + +So: + +* We no longer worry about MacPorts/Fink being installed<sup>[†](#_†)</sup> +* We no longer worry about system duplicates<sup>[†](#_†)</sup> +* We override common tools and fix them—we no longer have to do so with workarounds in affected formula, waiting for a fix from Apple. +* Builds are forcibly optimized how we want, and debug info forcibly removed. + +---- + +## Footnotes +<div style="color: #555; font-size: 85%"> + <ul> + <li><a id="_†"><sup>†</sup></a>: Nearly as much, anyway.</li> + <li><a id="_1"><sup>1</sup></a>: Formula can opt-into re-adding the user’s <code>PATH</code> again. Some formulae need this.</li> + <li><a id="_2"><sup>2</sup></a>: Indeed; this is selected based on Xcode version.</li> + </ul> +</div> |