Description of problem:
$ sudo dnf builddep pdns
enabling rawhide-source repository
Fedora - Rawhide - Source                                     6.8 MB/s | 5.9 MB     00:00    
Last metadata expiration check performed 0:00:01 ago on Sun Jul 26 11:50:54 2015.
Traceback (most recent call last):
  File "/usr/lib/python3.4/site-packages/dnf-plugins/builddep.py", line 154, in _src_deps
    h = self.rpm_ts.hdrFromFdno(fd)
  File "/usr/lib64/python3.4/site-packages/rpm/transaction.py", line 166, in hdrFromFdno
    raise rpm.error("public key not available")
_rpm.error: public key not available

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/bin/dnf", line 35, in <module>
    main.user_main(sys.argv[1:], exit_code=True)
  File "/usr/lib/python3.4/site-packages/dnf/cli/main.py", line 185, in user_main
    errcode = main(args)
  File "/usr/lib/python3.4/site-packages/dnf/cli/main.py", line 84, in main
    return _main(base, args)
  File "/usr/lib/python3.4/site-packages/dnf/cli/main.py", line 134, in _main
    cli.run()
  File "/usr/lib/python3.4/site-packages/dnf/cli/cli.py", line 1077, in run
    return self.command.run(self.base.extcmds)
  File "/usr/lib/python3.4/site-packages/dnf-plugins/builddep.py", line 71, in inner
    return func(*args, **kwds)
  File "/usr/lib/python3.4/site-packages/dnf-plugins/builddep.py", line 130, in run
    self._remote_deps(pkgspec)
  File "/usr/lib/python3.4/site-packages/dnf-plugins/builddep.py", line 194, in _remote_deps
    self._src_deps(pkg.localPkg())
  File "/usr/lib/python3.4/site-packages/dnf-plugins/builddep.py", line 156, in _src_deps
    if e[0] == 'public key not available':
TypeError: 'error' object does not support indexing


Version-Release number of selected component (if applicable):
This is on rawhide.

dnf-1.0.1-3.fc23.noarch
dnf-plugins-core-0.1.9-1.fc23.noarch

How reproducible:
Crashes again when I rerun the command.