Given what i know about the problem: substitute operations are failing
because gnutls is not available, I tried:
jackhill@kalessin ~$ guix build --substitute-urls=http://ci.guix.gnu.org
/gnu/store/zkhymfsbrv0s4y7l778g78k6y65nidxd-gnutls-3.6.16.drv
/gnu/store/2vjql2vd6srqxhr0r9xnhclqgc5kxlh1-gnutls-3.6.16-debug
/gnu/store/ads39f4czri8s1k43qd0qpxi6dr3w0zn-gnutls-3.6.16-doc
/gnu/store/jlk67v3nddhv0z963wfvahk8fc8gqcz8-gnutls-3.6.16
jackhill@kalessin ~$ ls -l
/gnu/store/jlk67v3nddhv0z963wfvahk8fc8gqcz8-gnutls-3.6.16
ls: cannot access
'/gnu/store/jlk67v3nddhv0z963wfvahk8fc8gqcz8-gnutls-3.6.16': No such file
or directory
So Guix think's it's sucessfully built gnutls, but it's still not
present in the store. I've also tried copying the store items from
other hosts. No luck so far…