Hello Tatiana!
An interesting command to test that everything works correctly is:
parallel 'echo {} && curl http://localhost:8080/' ::: {1..100}
You can use it on an example server:
./pre-inst-env cuirass --specifications=examples/random.scm --database=test.db
or
./pre-inst-env cuirass --specifications=examples/hello-singleton.scm
--database=test.db
It run 100 times 'curl http://localhost:8080/' in parallel, so it's good
at showing issues related to multi-threading.
(you need 'guix package -i parallel' :-))
Those issues are hard to debug, I'll investigate too.
Clément