First stab at "pub run" command.

sdk/lib/_internal/pub/test/version_solver_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library pub_upgrade_test;
 
 import 'dart:async';
 
 import 'package:unittest/unittest.dart';
 
 import '../lib/src/lock_file.dart';
 import '../lib/src/log.dart' as log;
 import '../lib/src/package.dart';
 import '../lib/src/pubspec.dart';
 import '../lib/src/sdk.dart' as sdk;
 import '../lib/src/source/cached.dart';
 import '../lib/src/system_cache.dart';
 import '../lib/src/utils.dart';
 import '../lib/src/version.dart';
 import '../lib/src/solver/version_solver.dart';
 import 'test_pub.dart';
 
 MockSource source1;
 MockSource source2;
 
 main() {
   initConfig();
 
   // Uncomment this to debug failing tests.
-  // log.showSolver();
+  // log.verbosity = log.Verbosity.SOLVER;
 
   // Since this test isn't run from the SDK, it can't find the "version" file
   // to load. Instead, just manually inject a version.
   sdk.version = new Version(1, 2, 3);
 
   group('basic graph', basicGraph);
   group('with lockfile', withLockFile);
   group('root dependency', rootDependency);
   group('dev dependency', devDependency);
   group('unsolvable', unsolvable);
@@ skipping 1019 matching lines @@
 testResolve(String description, Map packages, {
     Map lockfile, Map overrides, Map result, FailMatcherBuilder error,
     int maxTries}) {
   _testResolve(test, description, packages, lockfile: lockfile,
       overrides: overrides, result: result, error: error, maxTries: maxTries);
 }
 
 solo_testResolve(String description, Map packages, {
     Map lockfile, Map overrides, Map result, FailMatcherBuilder error,
     int maxTries}) {
-  log.showSolver();
+  log.verbosity = log.Verbosity.SOLVER;
   _testResolve(solo_test, description, packages, lockfile: lockfile,
       overrides: overrides, result: result, error: error, maxTries: maxTries);
 }
 
 _testResolve(void testFn(String description, Function body),
     String description, Map packages, {
     Map lockfile, Map overrides, Map result, FailMatcherBuilder error,
     int maxTries}) {
   if (maxTries == null) maxTries = 1;
 
@@ skipping 392 matching lines @@
   }
 
   var source = "mock1";
   if (match[7] != null) {
     source = match[7];
     if (source == "root") source = null;
   }
 
   return new PackageId(name, source, parsedVersion, description);
 }