The jepsen tests started failing after SERVER-85737 was merged. Upon inspection the mongod binary was hanging early in the process startup due to dead lock. Both tcmalloc and libfaketime use interceptors and this causes tcmalloc to get into a dead lock, in this case around the sys call clock_gettime. Similar issues have been reported for other processes which use interceptors: https://github.com/google/tcmalloc/issues/78

For now we will make jepsen tests use the old allocator. We should look into making new tcmalloc or libfaketime work together on new platforms for the future.