Cargo Features

Ftp4 has no features set by default.

[dependencies]
ftp4 = { version = "4.0.2", features = ["secure", "debug_print"] }
secure = native-tls

Enable support of FTPS which requires openssl

debug_print

Add debug output (to STDOUT) of commands sent to the server and lines read from the server

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.

native-tls secure?