diff --git a/pkgs/build-support/fetchurl/default.nix b/pkgs/build-support/fetchurl/default.nix index c65738aef41..8ce69a7f187 100644 --- a/pkgs/build-support/fetchurl/default.nix +++ b/pkgs/build-support/fetchurl/default.nix @@ -104,7 +104,9 @@ let if urls != [] && url == "" then (if lib.isList urls then urls else throw "`urls` is not a list") - else if urls == [] && url != "" then [url] + else if urls == [] && url != "" then + (if lib.isString url then [url] + else throw "`url` is not a string") else throw "fetchurl requires either `url` or `urls` to be set"; hash_ =