Switch to pretty_env_logger, under --features pretty-env-logger

Author: dwijnand

Cargo.toml

@@ -25,6 +25,7 @@ crypto-hash = "0.3.1"
 curl = { version = "0.4.19", features = ['http2'] }
 curl-sys = "0.4.15"
 env_logger = "0.6.0"
+pretty_env_logger = { version = "0.2", optional = true }
 failure = "0.1.2"
 filetime = "0.2"
 flate2 = { version = "1.0.3", features = ['zlib'] }
@@ -105,3 +106,4 @@ doc = false
 
 [features]
 vendored-openssl = ['openssl/vendored']
+pretty-env-logger = ['pretty_env_logger']

src/bin/cargo/main.rs

@@ -3,6 +3,9 @@
 
 extern crate cargo;
 extern crate clap;
+#[cfg(feature = "pretty-env-logger")]
+extern crate pretty_env_logger;
+#[cfg(not(feature = "pretty-env-logger"))]
 extern crate env_logger;
 #[macro_use]
 extern crate failure;
@@ -28,6 +31,9 @@ mod commands;
 use command_prelude::*;
 
 fn main() {
+    #[cfg(feature = "pretty-env-logger")]
+    pretty_env_logger::init();
+    #[cfg(not(feature = "pretty-env-logger"))]
     env_logger::init();
     cargo::core::maybe_allow_nightly_features();