Do not hide import errors [demos]
Do not hide import errors [demos]


Former-commit-id: fcbb613ebef6e323ec7f1e180ba605160fe85e0d [formerly eff46ea82eba7c836e7f3bed8bd4c5e7fa2f2deb]
Former-commit-id: e03cfc1200a3c7f9fb63e880fff65685cb753885
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine