> configure:3839: ./conftest
> dyld: Library not loaded: @rpath/CoreFoundation.framework/Versions/A/CoreFoundation
> Referenced from: /private/tmp/nix-build-racket-6.12.drv-0/racket-6.12/src/build/./conftest
> Reason: no suitable image found. Did find:
> /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation: file system sandbox blocked stat()

As it should. But LD_LIBRARY_PATH should have been set, and it isn't.