Add log variable to justfile (#621)

Allows logging to be controlled with, for example:

    just log=trace run

justfile

@@ -10,12 +10,19 @@ bt := '0'
 
 export RUST_BACKTRACE := bt
 
+log := "warn"
+
+export JUST_LOG := log
+
 test:
 	cargo test
 
 fuzz:
 	cargo +nightly fuzz run fuzz-compiler
 
+run:
+	cargo run
+
 @spam:
 	{ \
 		figlet test; \

src/common.rs

@@ -29,7 +29,7 @@ pub(crate) use crate::{node::Node, tree::Tree};
 pub(crate) use derivative::Derivative;
 pub(crate) use edit_distance::edit_distance;
 pub(crate) use libc::EXIT_FAILURE;
-pub(crate) use log::warn;
+pub(crate) use log::{info, warn};
 pub(crate) use snafu::{ResultExt, Snafu};
 pub(crate) use unicode_width::UnicodeWidthChar;
 

src/run.rs

@@ -13,6 +13,7 @@ pub fn run() -> Result<(), i32> {
 
   let app = Config::app();
 
+  info!("Parsing command line arguments…");
   let matches = app.get_matches();
 
   let config = Config::from_matches(&matches).eprint(Color::auto())?;