Always log stack traces for Error objects (#3586)

Closes #3585

The default logging omits stack traces by default and prints them only
in verbose mode. This is intended to allow builder implementations to
cease execution and log a user friendly message by throwing a single
`Exception` with a custom `toString()`. When a builder or utility
library has an implementation bug leading to an `Error` the stack trace
is much more likely to be useful information for debugging, and worth
including by default.

Author: natebosch

build_runner/CHANGELOG.md

@@ -1,6 +1,7 @@
 ## 2.4.8-wip
 
 - Update README.md to point to the FAQ and other docs.
+- Print stack traces for `Error` subtype exceptions in non-verbose mode.
 
 ## 2.4.7
 

build_runner/lib/src/logging/std_io_logging.dart

@@ -33,7 +33,7 @@ StringBuffer colorLog(LogRecord record, {required bool verbose}) {
     lines.add(record.error!);
   }
 
-  if (record.stackTrace != null && verbose) {
+  if (record.stackTrace != null && (verbose || record.error is Error)) {
     var trace = Trace.from(record.stackTrace!);
     const buildSystem = {'build_runner', 'build_runner_core', 'build'};
     if (trace.frames.isNotEmpty &&