diff --git a/src/land/engine/ArcanistGitLandEngine.php b/src/land/engine/ArcanistGitLandEngine.php
--- a/src/land/engine/ArcanistGitLandEngine.php
+++ b/src/land/engine/ArcanistGitLandEngine.php
@@ -174,10 +174,9 @@
           'Synchronizing "%s" from Perforce...',
           $target->getRef()));
 
-      $err = $api->execPassthru(
+      $err = $this->newPassthru(
         'p4 sync --silent --branch %s --',
         $target->getRemote().'/'.$target->getRef());
-
       if ($err) {
         throw new ArcanistUsageException(
           pht(
@@ -416,12 +415,11 @@
       // fix conflicts and run "arc land" again.
       $flags_argv[] = '--conflict=quit';
 
-      $err = $api->execPassthru(
+      $err = $this->newPassthru(
         '%LR p4 submit %LR --commit %R --',
         $config_argv,
         $flags_argv,
         $into_commit);
-
       if ($err) {
         throw new ArcanistUsageException(
           pht(
@@ -435,7 +433,7 @@
       pht('PUSHING'),
       pht('Pushing changes to "%s".', $this->getOntoRemote()));
 
-    $err = $api->execPassthru(
+    $err = $this->newPassthru(
       'push -- %s %Ls',
       $this->getOntoRemote(),
       $this->newOntoRefArguments($into_commit));
@@ -1298,9 +1296,7 @@
     $ignore_failure = false) {
     $api = $this->getRepositoryAPI();
 
-    // TODO: Format this fetch nicely as a workflow command.
-
-    $err = $api->execPassthru(
+    $err = $this->newPassthru(
       'fetch --no-tags --quiet -- %s %s',
       $target->getRemote(),
       $target->getRef());
diff --git a/src/land/engine/ArcanistLandEngine.php b/src/land/engine/ArcanistLandEngine.php
--- a/src/land/engine/ArcanistLandEngine.php
+++ b/src/land/engine/ArcanistLandEngine.php
@@ -1548,4 +1548,20 @@
     return $sets;
   }
 
+  final protected function newPassthru($pattern /* , ... */) {
+    $workflow = $this->getWorkflow();
+    $argv = func_get_args();
+
+    $api = $this->getRepositoryAPI();
+
+    $passthru = call_user_func_array(
+      array($api, 'newPassthru'),
+      $argv);
+
+    $command = $workflow->newCommand($passthru)
+      ->setResolveOnError(true);
+
+    return $command->execute();
+  }
+
 }
diff --git a/src/land/engine/ArcanistMercurialLandEngine.php b/src/land/engine/ArcanistMercurialLandEngine.php
--- a/src/land/engine/ArcanistMercurialLandEngine.php
+++ b/src/land/engine/ArcanistMercurialLandEngine.php
@@ -360,14 +360,14 @@
 
     // TODO: Support bookmarks.
     // TODO: Deal with bookmark save/restore behavior.
-    // TODO: Format this nicely with passthru.
     // TODO: Raise a good error message when the ref does not exist.
 
-    $api->execPassthru(
+    $err = $this->newPassthru(
       'pull -b %s -- %s',
       $target->getRef(),
       $target->getRemote());
 
+    // TODO: Deal with errors.
     // TODO: Deal with multiple branch heads.
 
     list($stdout) = $api->execxLocal(
@@ -507,7 +507,7 @@
 
     // TODO: This does not respect "--into" or "--onto" properly.
 
-    $api->execxLocal(
+    $this->newPassthru(
       'push --rev %s -- %s',
       hgsprintf('%s', $into_commit),
       $this->getOntoRemote());
diff --git a/src/repository/api/ArcanistGitAPI.php b/src/repository/api/ArcanistGitAPI.php
--- a/src/repository/api/ArcanistGitAPI.php
+++ b/src/repository/api/ArcanistGitAPI.php
@@ -20,12 +20,11 @@
   protected function buildLocalFuture(array $argv) {
     $argv[0] = 'git '.$argv[0];
 
-    $future = newv('ExecFuture', $argv);
-    $future->setCWD($this->getPath());
-    return $future;
+    return newv('ExecFuture', $argv)
+      ->setCWD($this->getPath());
   }
 
-  public function execPassthru($pattern /* , ... */) {
+  public function newPassthru($pattern /* , ... */) {
     $args = func_get_args();
 
     static $git = null;
@@ -43,10 +42,10 @@
 
     $args[0] = $git.' '.$args[0];
 
-    return call_user_func_array('phutil_passthru', $args);
+    return newv('PhutilExecPassthru', $args)
+      ->setCWD($this->getPath());
   }
 
-
   public function getSourceControlSystemName() {
     return 'git';
   }
diff --git a/src/repository/api/ArcanistMercurialAPI.php b/src/repository/api/ArcanistMercurialAPI.php
--- a/src/repository/api/ArcanistMercurialAPI.php
+++ b/src/repository/api/ArcanistMercurialAPI.php
@@ -27,18 +27,16 @@
     return $future;
   }
 
-  public function execPassthru($pattern /* , ... */) {
+  public function newPassthru($pattern /* , ... */) {
     $args = func_get_args();
 
     $env = $this->getMercurialEnvironmentVariables();
 
     $args[0] = 'hg '.$args[0];
 
-    $passthru = newv('PhutilExecPassthru', $args)
+    return newv('PhutilExecPassthru', $args)
       ->setEnv($env)
       ->setCWD($this->getPath());
-
-    return $passthru->resolve();
   }
 
   public function getSourceControlSystemName() {
diff --git a/src/repository/api/ArcanistRepositoryAPI.php b/src/repository/api/ArcanistRepositoryAPI.php
--- a/src/repository/api/ArcanistRepositoryAPI.php
+++ b/src/repository/api/ArcanistRepositoryAPI.php
@@ -675,6 +675,20 @@
       ->setResolveOnError(false);
   }
 
+  public function newPassthru($pattern /* , ... */) {
+    throw new PhutilMethodNotImplementedException();
+  }
+
+  final public function execPassthru($pattern /* , ... */) {
+    $args = func_get_args();
+
+    $future = call_user_func_array(
+      array($this, 'newPassthru'),
+      $args);
+
+    return $future->resolve();
+  }
+
   final public function setRuntime(ArcanistRuntime $runtime) {
     $this->runtime = $runtime;
     return $this;
diff --git a/src/toolset/command/ArcanistCommand.php b/src/toolset/command/ArcanistCommand.php
--- a/src/toolset/command/ArcanistCommand.php
+++ b/src/toolset/command/ArcanistCommand.php
@@ -5,6 +5,7 @@
 
   private $logEngine;
   private $executableFuture;
+  private $resolveOnError = false;
 
   public function setExecutableFuture(PhutilExecutableFuture $future) {
     $this->executableFuture = $future;
@@ -24,6 +25,15 @@
     return $this->logEngine;
   }
 
+  public function setResolveOnError($resolve_on_error) {
+    $this->resolveOnError = $resolve_on_error;
+    return $this;
+  }
+
+  public function getResolveOnError() {
+    return $this->resolveOnError;
+  }
+
   public function execute() {
     $log = $this->getLogEngine();
     $future = $this->getExecutableFuture();
@@ -41,7 +51,7 @@
 
     $log->writeNewline();
 
-    if ($err) {
+    if ($err && !$this->getResolveOnError()) {
       $log->writeError(
         pht('ERROR'),
         pht(
@@ -55,5 +65,7 @@
         '',
         '');
     }
+
+    return $err;
   }
 }