Segfault during TClass::GetClass for missing dictionary

Reading the attached file and then calling {{TClass::GetClass("std::vector<artdaq::Fragment>")} results in a segmentation violation.

{{[knoepfel@woof ~]$ root -l ~greenc/tmp/lariat_r005214_sr0002.root
root [0]
Attaching file /home/greenc/tmp/lariat_r005214_sr0002.root as _file0...
Warning in <TClass::Init>: no dictionary for class art::BranchKey is available
Warning in <TClass::Init>: no dictionary for class art::BranchDescription is available
Warning in <TClass::Init>: no dictionary for class art::BranchID is available
Warning in <TClass::Init>: no dictionary for class fhicl::ParameterSetID is available
Warning in <TClass::Init>: no dictionary for class boost::array<unsigned char,20> is available
Warning in <TClass::Init>: no dictionary for class art::Hash<3> is available
Warning in <TClass::Init>: no dictionary for class art::Transient<art::BranchDescription::Transients> is available
Warning in <TClass::Init>: no dictionary for class art::Hash<2> is available
Warning in <TClass::Init>: no dictionary for class art::ProcessHistory is available
Warning in <TClass::Init>: no dictionary for class art::ProcessConfiguration is available
Warning in <TClass::Init>: no dictionary for class art::Transient<art::ProcessHistory::Transients> is available
Warning in <TClass::Init>: no dictionary for class art::EventAuxiliary is available
Warning in <TClass::Init>: no dictionary for class art::EventID is available
Warning in <TClass::Init>: no dictionary for class art::RunID is available
Warning in <TClass::Init>: no dictionary for class art::SubRunID is available
Warning in <TClass::Init>: no dictionary for class art::Timestamp is available
Warning in <TClass::Init>: no dictionary for class art::SubRunAuxiliary is available
Warning in <TClass::Init>: no dictionary for class art::RunAuxiliary is available
Warning in <TClass::Init>: no dictionary for class art::Wrapper<vector<artdaq::Fragment> > is available
Warning in <TClass::Init>: no dictionary for class art::EDProduct is available
Warning in <TClass::Init>: no dictionary for class artdaq::Fragment is available
Warning in <TClass::Init>: no dictionary for class artdaq::QuickVec<ULong64_t> is available
Warning in <TClass::Init>: no dictionary for class art::Wrapper<art::TriggerResults> is available
Warning in <TClass::Init>: no dictionary for class art::TriggerResults is available
Warning in <TClass::Init>: no dictionary for class art::HLTGlobalStatus is available
Warning in <TClass::Init>: no dictionary for class art::DoNotRecordParents is available
Warning in <TClass::Init>: no dictionary for class art::Wrapper<vector<artdaq::PackageBuildInfo> > is available
Warning in <TClass::Init>: no dictionary for class artdaq::PackageBuildInfo is available
Warning in <TClass::Init>: no dictionary for class art::History is available
Warning in <TClass::Init>: no dictionary for class art::ProductProvenance is available
Warning in <TClass::Init>: no dictionary for class art::Hash<5> is available
Warning in <TClass::Init>: no dictionary for class art::Transient<art::ProductProvenance::Transients> is available
Warning in <TClass::Init>: no dictionary for class art::HLTPathStatus is available
Warning in <TClass::Init>: no dictionary for class art::FileFormatVersion is available
Warning in <TClass::Init>: no dictionary for class art::FileIndex is available
Warning in <TClass::Init>: no dictionary for class art::Transient<art::FileIndex::Transients> is available
Warning in <TClass::Init>: no dictionary for class art::FileIndex::Element is available
Warning in <TClass::Init>: no dictionary for class pair<const art::Hash<2>,art::ProcessHistory> is available
Warning in <TClass::Init>: no dictionary for class art::ProductRegistry is available
Warning in <TClass::Init>: no dictionary for class pair<art::BranchKey,art::BranchDescription> is available
Warning in <TClass::Init>: no dictionary for class art::Parentage is available
Warning in <TClass::Init>: no dictionary for class art::BranchChildren is available
Warning in <TClass::Init>: no dictionary for class pair<art::BranchID,set<art::BranchID> > is available
(TFile *) 0x2c86040
root [1] TClass::GetClass("std::vector<artdaq::Fragment>")

• • • Break *** segmentation violation
      Root >
      }}

I would expect it to return a nullptr, or something equivalent.