Unclear how to enable profiling

[thijsc]

I'm trying to get jemalloc to do heap profiling by configuring it in the environment:

export MALLOC_CONF=prof:true,lg_prof_interval:30,lg_prof_sample:17

Profiling is enabled:

[dependencies.jemallocator]
version = "*"
features = ["profiling"]

I do not see the expected output as described here. Is this expected to work when using this crate?