Cargo Features

tracers-libelf-sys has no features set by default.

tracers-libelf-sys = { version = "0.1.0", features = ["enabled", "required"] }

by default, building libelf is disabled. It must be explicitly enabled

enabled = libc, libz-sys

if this feature is enabled, then the will try to build the libelf binaries.
if the build fails, this crate's build will still succeed
The success or failure of the build will be communicated via a variable in cargo,
which dependent crates can resolve with DEP_LIBELF_SYS_SUCCEEDED

required = libc, libz-sys

If this feature is enabled, it implies enabled, and also will cause the build to fail if libelf cannot be built

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features.

libz-sys enabled? required?
libc enabled? required?