message: Extract iPhone SDK path into a variable
diff: @@ -25,9 +25,10 @@ CXXFLAGS=-g -Wall -Wextra -Wno-missing-field-initializers -Werror -std=c++98
  LDFLAGS=
  ifeq ($(config),iphone)
  - CFLAGS+=-arch armv7 -arch arm64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk
  - CXXFLAGS+=-arch armv7 -arch arm64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk -stdlib=libc++
  - LDFLAGS+=-arch armv7 -arch arm64 -L /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/lib -mios-version-min=7.0
  + IPHONESDK=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk
  + CFLAGS+=-arch armv7 -arch arm64 -isysroot $(IPHONESDK)
  + CXXFLAGS+=-arch armv7 -arch arm64 -isysroot $(IPHONESDK) -stdlib=libc++
  + LDFLAGS+=-arch armv7 -arch arm64 -L $(IPHONESDK)/usr/lib -mios-version-min=7.0
  endif
  ifeq ($(config),release)
  