feat(cli): do not run executable if build failed

cli/src/build.rs

@@ -204,12 +204,15 @@ pub fn build_file<'a>(
 
     let total_time = compilation_start.elapsed().unwrap();
 
+    // TODO change this to report whether there were errors or warnings!
+    let outcome = match &cmd_result {
+        Ok(exit_status) if exit_status.success() => BuildOutcome::NoProblems,
+        _ => BuildOutcome::Errors,
+    };
+
     // If the cmd errored out, return the Err.
     cmd_result?;
 
-    // TODO change this to report whether there were errors or warnings!
-    let outcome = BuildOutcome::NoProblems;
-
     Ok(BuiltFile {
         binary_path,
         outcome,

cli/src/lib.rs

@@ -231,7 +231,10 @@ pub fn build(target: &Triple, matches: &ArgMatches, config: BuildConfig) -> io::
                         }
                     }
 
-                    roc_run(cmd.current_dir(original_cwd))
+                    match outcome {
+                        BuildOutcome::Errors => Ok(2),
+                        _ => roc_run(cmd.current_dir(original_cwd)),
+                    }
                 }
             }
         }