From 5ce1d7971746f8bf933d69607219f16de93c9e4f Mon Sep 17 00:00:00 2001
From: epriestley <git@epriestley.com>
Date: Thu, 2 Apr 2020 08:14:18 -0700
Subject: [PATCH] Fix error behavior of "arc version" when it encounters a
 library which is not a working copy

Summary:
Ref T13504. The API has changed here slightly, and if you run "arc version" without "arcanist/" being a Git working copy, it currently fatals in a misleading way.

Instead, reach the error properly.

Test Plan: Ran "arc version" after moving aside ".git/", got a helpful error message instead of a confusing "call on null" exception.

Maniphest Tasks: T13504

Differential Revision: https://secure.phabricator.com/D21050
---
 .../workflow/ArcanistVersionWorkflow.php      | 20 +++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/toolset/workflow/ArcanistVersionWorkflow.php b/src/toolset/workflow/ArcanistVersionWorkflow.php
index f004f855..eafca523 100644
--- a/src/toolset/workflow/ArcanistVersionWorkflow.php
+++ b/src/toolset/workflow/ArcanistVersionWorkflow.php
@@ -48,15 +48,23 @@ EOTEXT
     );
 
     foreach ($roots as $lib => $root) {
-      $working_copy = ArcanistWorkingCopy::newFromWorkingDirectory($root);
-      $repository_api = $working_copy->newRepositoryAPI();
+      $is_git = false;
 
-      if (!$repository_api instanceof ArcanistGitAPI) {
-        throw new ArcanistUsageException(
+      $working_copy = ArcanistWorkingCopy::newFromWorkingDirectory($root);
+      if ($working_copy) {
+        $repository_api = $working_copy->newRepositoryAPI();
+        if ($repository_api instanceof ArcanistGitAPI) {
+          $is_git = true;
+        }
+      }
+
+      if (!$is_git) {
+        throw new PhutilArgumentUsageException(
           pht(
-            'Library "%s" is not a Git working copy, so no version '.
+            'Library "%s" (at "%s") is not a Git working copy, so no version '.
             'information can be provided.',
-            $lib));
+            $lib,
+            Filesystem::readablePath($root)));
       }
 
       // NOTE: Carefully execute these commands in a way that works on Windows