Tinygo help fixing build on darwin

I am trying to fix vendor rebuild for tinygo

builds on Linux but on darwin I get

       > cgo-builtin-prolog:1:10: fatal error: 'stddef.h' file not found
       > #include <stddef.h>
       >          ^~~~~~~~~~
       > 1 error generated.
       > # go.bug.st/serial/enumerator
       > cgo-builtin-prolog:1:10: fatal error: 'stddef.h' file not found
       > #include <stddef.h>
       >          ^~~~~~~~~~
       > 1 error generated.
       For full logs, run 'nix log /nix/store/gd9f960w4x51l8x82l6siacgfv8a5f2q-tinygo-0.26.0.drv'.

it almost looks like clang completely broken … its using same clang.cc as on master which builds

:person_shrugging: