tracers-dyn-stap has no features set by default.
by default, building the stap provider is disabled. It must be explicitly enabled
if this feature is enabled, then the build.rs will try to build the stap provider's dependencies, libstapstd-sys (and, transitively, libelf-sys).
if the build fails, this crate's build will still succeed, but the stap provider's code will not be included in the resulting crate.
The success or failure of the build will be communicated via a variable in cargo,
which dependent crates can resolve with DEP_TRACERS_STAP_SUCCEEDED
If this feature is enabled, it implies
enabled, and also will cause the build to fail if the stap provider cannot be built
Features from optional dependencies
In crates that don't use the
dep: syntax, optional dependencies automatically become Cargo features.