Am Sonntag, 20. Januar 2013 schrieb Ludovic Courtès:
> > $ guix-package -i netpbm
> > error: build failed: build of
> > `/nix/store/h2s02132641hvaqr03q96i97dydlqm4i- user-environment.drv'
> > failed.
> Can you run it with --verbose?

Ah, so many options! I tried the daemon with --debug. Here is the result:
In unknown file:
   ?: 0 [mkdir "/nix/store/mv7v3y702k1yfml8067gn15r3n6pzjxm-user-
environment///nix/store/agjc4rdsvi4wvbz6dymgid5pb85nqcf7-
netpbm-10.61.01/VERSION" ...]
ERROR: In procedure mkdir:
ERROR: In procedure mkdir: No such file or directory

So indeed, the problem is the extraneous files, and the package can be 
installed after deleting them.

> OK, it’s probably a generated tarball from a checkout.  Can you just add
> these links to the file?

Yes, I just read one could also do an svn checkout from a tag.

New patch attached.

Andreas