bug#28602: Unpack fails with no error message when using a .zip source

[nee]

Am 04.10.2017 um 20:17 schrieb Adonay Felipe Nogueira:
> Does the .zip file have a a single directory on the root?
> 
> If not, then we can call it a zipbomb/tarbomb. These bombs are bad
> because they can replace things without notice, and can be very
> difficult to track what was added. Last time I checked Guix expects only
> a single directory in the root of the file --- this might have changed,
> but I didn't test it since one year ago.

Hello, this is a different problem. Tarbombs are still a problem, but
unrelated to this.

The gnu-build-system does not have unzip by default. If a package's
source comes in a zip the package must have unzip as native-input. If it
isn't the (system* "unzip" source) call in the unpack function will fail
because there is no unzip executable.

Happy hacking!