Thanks a lot for testing this cutting edge version!

In the meantime I could reproduce this error message by running a
simulated diff update via:

  ../src/test-bin/run_testsuite_diff_updater.sh 200

in the osm-3s_testing directory. I also got similar crashes on a db
reorg step, when importing a fresh Germany extract.

I pushed a small fix to the backend_compression_lz4_map branch now.
Also, I reran that particular testsuite step as well as a Germany
import, both of which worked fine.