Cargo Features

vm-fdt = { version = "0.3.0", default-features = false, features = ["std", "alloc", "long_running_test"] }
default = std

The std feature is set by default whenever vm-fdt is added without default-features = false somewhere in the dependency tree.

std default
alloc = hashbrown

This feature was added as a way to exclude long running tests in development. cargo test does not run tests for all features by default. The vm-fdt developer can thus choose to "hide" a long running under this feature. One example of a long running test is the test that checks for overflows caused by large memory allocations.

The rust-vmm-ci will still run these tests.

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features. These features may have been created by mistake, and this functionality may be removed in the future.

hashbrown alloc?