these 2 derivations will be built:
  /nix/store/vjif1pbr0rxl71x8d86bjncr0agz62in-closure-info.drv
  /nix/store/b26xj8lfi92bh2psp9hcbjj38nby7c2b-check-vars.drv
error: path '/nix/store/3bmz3f8frg9dff1qabl48m0bjk3i0927-source' is not valid
error: Cannot build '/nix/store/b26xj8lfi92bh2psp9hcbjj38nby7c2b-check-vars.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/f9hqwalb2r24mg9izbj5gwv2l0swask7-check-vars