Rust tests fail under tarpaulin

Relevant section of most recent CI log appears to be:

Processing ekiden-storage-batch
Launching test
running /root/project/target/debug/deps/ekiden_storage_batch-d66081ef95292753

running 1 test
test backend::test::test_batch ... ok

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

Error occurred when handling ptrace event: ESRCH: No such process
Processing ekiden-enclave-common
Launching test
running /root/project/target/debug/deps/ekiden_enclave_common-460abce2f57fcf07
Unexpected signal when starting test

running 2 tests
test quote::tests::test_pem_parse_many ... ok
test quote::tests::test_validate_avr_signature ... ok

test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

so it's likely either the enclave_common or the storage_batch test that should be excluded or debugged in this context

Start with the tarpaulin CI run and the tests named in the log: ekiden-storage-batch's backend::test::test_batch and ekiden-enclave-common's quote tests. Investigate the ESRCH ptrace error and unexpected signal, then determine whether either test needs debugging or exclusion under tarpaulin. Done means the relevant Rust tests run successfully in that coverage context without the reported failure.