Merge pull request #154 from antonok-edm/build-diagnostic-improvements

`cargo build` diagnostic improvements

Author: adamgreig

src/lib.rs

@@ -417,7 +417,7 @@ fn cargo_build(matches: &ArgMatches, metadata: &Metadata) -> Result<Option<Artif
     let (build_type, verbose) = cargo_build_args(matches, &mut cargo);
     let quiet = matches.get_flag("quiet");
 
-    cargo.arg("--message-format=json");
+    cargo.arg("--message-format=json-diagnostic-rendered-ansi");
     cargo.stdout(Stdio::piped());
 
     if verbose > 0 {
@@ -431,9 +431,6 @@ fn cargo_build(matches: &ArgMatches, metadata: &Metadata) -> Result<Option<Artif
     let messages = Message::parse_stream(stdout).collect::<Vec<_>>();
 
     let status = child.wait()?;
-    if !status.success() {
-        bail!("Failed to parse crate metadata");
-    }
 
     let mut target_artifact: Option<Artifact> = None;
     for message in messages {
@@ -460,6 +457,10 @@ fn cargo_build(matches: &ArgMatches, metadata: &Metadata) -> Result<Option<Artif
         }
     }
 
+    if !status.success() {
+        bail!("Failed to parse crate metadata");
+    }
+
     if target_artifact.is_none() {
         bail!("Could not determine the wanted artifact");
     }