Constant KTSTR_JEMALLOC_ALLOC_WORKER_BINARY_ENV 

pub const KTSTR_JEMALLOC_ALLOC_WORKER_BINARY_ENV: &str = "KTSTR_JEMALLOC_ALLOC_WORKER_BINARY";

Name of the environment variable that points at a worker binary for jemalloc allocation-probe runs. Empty / unset leaves the worker binary unwired — same shape as KTSTR_JEMALLOC_PROBE_BINARY_ENV; the crate::test_support::runtime builder-wiring site calls .jemalloc_alloc_worker_binary() only on set+non-empty, no which-based fallback. Set alongside the probe via #[ctor] in tests/jemalloc_probe_tests.rs.