[TxMt] Building with a different SDK

[Ryan Schmidt]

Hi,

I'm trying to fix the textmate2 port in MacPorts. It fails to build on OS X 10.10 and earlier, and I think the reason is that the code uses Objective-C lightweight generics, a feature introduced in the 10.11 SDK. So I would like to instruct the build to use the 10.11 SDK, but I can't figure out how to do that. Usually I would set environment variables:

CFLAGS='-isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk'
CPPFLAGS='-isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk'
CXXFLAGS='-isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk'
LDFLAGS='-Wl,-syslibroot,/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk'
OBJCFLAGS='-isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk'
OBJCXXFLAGS='-isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk'

But textmate's configure script isn't an autotools one and it doesn't appear to honor these environment variables. So how can I tell the build system I want to use a different SDK? I see that the configure script explicitly passes CC and CXX to bin/gen_build. Do I need to modify the configure script to also explicitly pass the other environment variables or is there an easier way that doesn't involve modifying the build system?