diff options
Diffstat (limited to 'src/nix/prefetch.cc')
| -rw-r--r-- | src/nix/prefetch.cc | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/src/nix/prefetch.cc b/src/nix/prefetch.cc index f2dd44ba4..ce3288dc1 100644 --- a/src/nix/prefetch.cc +++ b/src/nix/prefetch.cc @@ -199,11 +199,13 @@ static int main_nix_prefetch_url(int argc, char * * argv) state->forceAttrs(v, noPos); /* Extract the URL. */ - auto & attr = v.attrs->need(state->symbols.create("urls")); - state->forceList(*attr.value, noPos); - if (attr.value->listSize() < 1) + auto * attr = v.attrs->get(state->symbols.create("urls")); + if (!attr) + throw Error("attribute 'urls' missing"); + state->forceList(*attr->value, noPos); + if (attr->value->listSize() < 1) throw Error("'urls' list is empty"); - url = state->forceString(*attr.value->listElems()[0]); + url = state->forceString(*attr->value->listElems()[0]); /* Extract the hash mode. */ auto attr2 = v.attrs->get(state->symbols.create("outputHashMode")); |