FixesHomebrew/homebrew#14554.
We justify doing this because pre 10.8 X11 came with GL for all Homebrew-capable systems and as such is a default that we'd prefer not to have to address.
Two wrapper scripts that find git and svn using the ENV variables we support and then searching through the PATH and looking inside Xcode.app if necessary.
Now just calling git or svn in Homebrew code will find and exec the right tool and we can stop fussing.
Apologies to @adamv who is probably unimpressed that the cmds directory has non-commands in it now. If it's consolation these are temporary pending some more work on superenv whereby some more directories are created under the superenv root.
1. A minimal build environment, we don't set CFLAGS, CPPFLAGS, LDFLAGS, etc. the rationale being, the less that is set, the less variables we are introducing that can break builds.
2. A set of scripts that replace cc, ld, etc. and inject the -I, -L, etc. flags we need into the args passed to the build-tools.
Because we now have complete control over compiler instantiations we do a variety of clean-up tasks, like removing bad flags, enforcing universal builds and ensuring makefiles don't try to change the order of library and include paths from ones that work to ones that don't.
The previous ENV-system is still available when --env=std is specified.
superenv applies to Xcode >= 4.3 only currently.
`brew install > file` should not give "export CC=/foo" output on Build Failures.
Also moved the "Using clang" output to brew when BuildError is thrown as that is where it is interesting, and not if you just do `brew --env`.
Using xcrun as a proxy to execute the compiler tools is per its design. This means you can't treat ENV['CC'] as a path anymore, but I think I found the cases this was being expected and corrected them. It was not proper anyway to assume the variable was a path, it can be anything. Like a proxy. Like xcrun.
Also more thoroughly clear ENV.
This allows you to use llvm as your default compiler and keep the cc symlink
pointed at llvm, while allowing you to build forumla that requires the gcc.
Signed-off-by: Adam Vandenberg <flangy@gmail.com>
The code was sucking. To the extent that maintenance was hard. It's a lot
easier to work with code that is sensibly split at sensible boundaries. So
now it is more like that.
But the refactor is minimal. Because we don't want you to have more merge
hell than absolutely necessary.
If you merge you will need to pay attention to brew.h.rb (as it is deleted)
and bin/brew (as command logic is gone). It will be painful, but you will just
have to help git out by moving any changes around manually.
Note compatibility.rb. It ensures that any function renames or removals don't
break anything. We're pretty serious about backwards compatibility. And that's
because we encourage you to hack around with the innards. And we couldn't do
that if we would then just make stuff disappear behind your back.
