Cargo Features

json_env_logger2 has no features set by default.

[dependencies]
json_env_logger2 = { version = "0.2.1", features = ["iso-timestamps", "backtrace"] }
iso-timestamps = chrono

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.

backtrace implicit feature

Enables backtrace

backtrace:

A library to acquire a stack trace (backtrace) at runtime in a Rust program

chrono iso-timestamps?