Escape arguments in pub error message command line reproduction.

sdk/lib/_internal/pub/lib/src/command_runner.dart

Index: sdk/lib/_internal/pub/lib/src/command_runner.dart
diff --git a/sdk/lib/_internal/pub/lib/src/command_runner.dart b/sdk/lib/_internal/pub/lib/src/command_runner.dart
index 96382da2b218b865dd7a81c9a573ee2c40314a31..ce0645d932b96a6ffcba6217b30ac8262baa599b 100644
--- a/sdk/lib/_internal/pub/lib/src/command_runner.dart
+++ b/sdk/lib/_internal/pub/lib/src/command_runner.dart
@@ -130,10 +130,12 @@ class PubCommandRunner extends CommandRunner {
       if (options['trace']) {
         log.dumpTranscript();
       } else if (!isUserFacingException(error)) {
+        // TODO(23505): Implement proper shell escaping, not a partial hack.
+        protectArgument(String x) => x.contains(' ') ? '"$x"' : x;

[nweiz, 2015/05/22 20:01:34]

Nit: don't type-annotate local variables, including parameters for local
functions.

         log.error("""
 This is an unexpected error. Please run
 
-    pub --trace ${options.arguments.map((arg) => "'$arg'").join(' ')}
+    pub --trace ${options.arguments.map(protectArgument).join(' ')}
 
 and include the results in a bug report on http://dartbug.com/new.
 """);