Bug in ArchiveReader
In querying a msgpack archive for a entry that is not part of the archive, the code goes an infinite loop ca. line 363 in archive.py.
In the latest v0.8.0 commit (01.03), I included a test springer msgpack database which can be used to verify this behavior. For example one can do
from nomad.archive import query_archive
q = query_archive('springer.msg', {'281':'*'})
Spacegroup '281' of course is not part of the archive.