BOOT_LDFLAGS

brew install gcc 卡住解决方法
brew install gcc
进行到

make BOOT_LDFLAGS=-Wl,-headerpad_max_install_names
的时候就卡住了，并且风扇狂转。
解决方法：安装 Xcode clt (Xcode command line tools)

$ xcode-select –install

$xcode-select –install
xcode-select: error: command line tools are already installed, use “Software Update” to install updates

https://learnku.com/articles/44890
https://stackoverflow.com/questions/22053776/how-to-override-prevent-or-revert-homebrews-changes-to-compilation-flags
https://github.com/Homebrew/homebrew-core/issues/37678

https://stackoverflow.com/questions/24966404/brew-install-gcc-too-time-consuming

https://discourse.brew.sh/t/building-gcc-for-a-different-architecture/2593