this derivation will be built:
  /nix/store/lsyg1r0qyhmlaj4bry2wscdfcdkvv77i-fail-5.drv
building '/nix/store/lsyg1r0qyhmlaj4bry2wscdfcdkvv77i-fail-5.drv'
fail-5> tribuchet: building on jamie
fail-5> this build is supposed to fail
error: Cannot build '/nix/store/lsyg1r0qyhmlaj4bry2wscdfcdkvv77i-fail-5.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/nj61sdcxs6whq4sj2wkcqh7ynkshj9hj-fail-5
       Last 2 log lines:
       > tribuchet: building on jamie
       > this build is supposed to fail
       For full logs, run:
         nix log /nix/store/lsyg1r0qyhmlaj4bry2wscdfcdkvv77i-fail-5.drv