Report error when parsing for line number selection

This makes the failure a little less mysterious.

Author: novemberborn

lib/reporters/default.js

@@ -220,6 +220,9 @@ export default class Reporter {
 				this.lineNumberErrors.push(event);
 
 				this.write(colors.information(`${figures.warning} Could not parse ${this.relativeFile(event.testFile)} for line number selection`));
+				this.lineWriter.writeLine();
+				this.lineWriter.writeLine(colors.errorStack(event.err.stack));
+				this.lineWriter.writeLine();
 				break;
 			}