$ spack spec -I [email protected]
==> Error: object of type 'NoneType' has no len()

Traceback (most recent call last):
  File "/project/csstaff/ialberto/opt/spack-daint/bin/spack", line 54, in <module>
    sys.exit(main())
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack_installable/main.py", line 37, in main
    sys.exit(spack.main.main(argv))
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/main.py", line 1004, in main
    return _main(argv)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/main.py", line 959, in _main
    return finish_parse_and_run(parser, cmd_name, env_format_error)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/main.py", line 987, in finish_parse_and_run
    return _invoke_command(command, parser, args, unknown)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/main.py", line 636, in _invoke_command
    return_val = command(parser, args)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/cmd/spec.py", line 103, in spec
    concretized_specs = spack.cmd.parse_specs(args.specs, concretize=True)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/cmd/__init__.py", line 222, in parse_specs
    spec.concretize(tests=tests)  # implies normalize
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/spec.py", line 2821, in concretize
    self._new_concretize(tests)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/spec.py", line 2796, in _new_concretize
    result = solver.solve([self], tests=tests)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/solver/asp.py", line 2539, in solve
    result, _, _ = self.driver.solve(setup, specs, reuse=reusable_specs, output=output)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/solver/asp.py", line 686, in solve
    setup.setup(self, specs, reuse=reuse)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/solver/asp.py", line 2137, in setup
    self.define_version_constraints()
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/solver/asp.py", line 1881, in define_version_constraints
    v for v in sorted(self.possible_versions[pkg_name]) if v.intersects(versions)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/solver/asp.py", line 1881, in <listcomp>
    v for v in sorted(self.possible_versions[pkg_name]) if v.intersects(versions)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/version.py", line 111, in coercing_method
    return getattr(ca, method.__name__)(cb, *args, **kwargs)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/version.py", line 1059, in intersects
    return self.overlaps(other)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/version.py", line 108, in coercing_method
    return method(a, b, *args, **kwargs)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/version.py", line 1050, in overlaps
    if self[s].overlaps(other[o]):
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/version.py", line 488, in overlaps
    return self.intersects(other)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/version.py", line 111, in coercing_method
    return getattr(ca, method.__name__)(cb, *args, **kwargs)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/version.py", line 108, in coercing_method
    return method(a, b, *args, **kwargs)
  File "/project/csstaff/ialberto/opt/spack-daint/lib/spack/spack/version.py", line 619, in intersects
    n = min(len(v1), len(v2))
TypeError: object of type 'NoneType' has no len()