I hadn't noticed this comment at the time. I said "patently" as in easy to check even if you think the docs are fiction, so for archives' sake: GNU's not Unix

I hadn't noticed this comment at the time. I said "patently" as in easy to check even if you think the docs are fiction, so for archives' sake: GNU's not Unix and there isn't a /usr/include in the build chroot; see the manual about that and profiles. $ cat x.c #include <stdlib.h> $ guix environment gcc $ gcc -Wp,-H x.c |& grep stdlib.h . /gnu/store/fc363b1hsid7pfdxh18m4a1i1r04i5fl-profile/include/stdlib.h $ readlink . /gnu/store/fc363b1hsid7pfdxh18m4a1i1r04i5fl-profile/include/stdlib.h /gnu/store/4sqaib7c2dfjv62ivrg9b8wa7bh226la-glibc-2.26.105-g0890d5379c/include/stdlib.h