Building software on Mac is always a pain, for anything that require clang/cc/gcc. Because some tooling come from homebrew, some come from Xcode. And when from XCode, there is two way, one in /Library/Developer/CommandLineTools and other in /Applications/Xcode.app/Contents/Developer. Depends on a lot of factor around your path and env, sometime error happen and really hard to debug if you’re familiar with C.

Today, I want to share a quick note on this error:

When you run go build and get this error

# runtime/cgo
_cgo_export.c:3:10: fatal error: 'stdlib.h' file not found

Then check your PATH, chance is you have something llvm path in your PATH so cland binary will be from homebrew:

/opt/homebrew/opt/llvm@[version-here]/bin/clang

You need to remove it, either unlink it, remove it, or update your path to switch to the right cland from xcode commandline tool.

$ which clang
/usr/bin/clang

A simple fix could be.