Move PATH checks to post-install

Summary:
We no longer need to do PHP CLI checks (D4568) or run `git submodule` (D4581) so we don't need $PATH to be set to complete setup. Move it to post-install.

Drop the instructions about PHP-FPM because the Phabricator config is dramatically easier now that we have it.

Test Plan: Set environment.append-paths to various things, faked lack of $PATH, verified I got the warning when I expected to setting Phabricator config cleared it.

Reviewers: codeblock, btrahan

Reviewed By: codeblock

CC: aran

Maniphest Tasks: T2228

Differential Revision: https://secure.phabricator.com/D4585

src/__phutil_library_map__.php

@@ -1219,6 +1219,7 @@ phutil_register_library_map(array(
     'PhabricatorSetupCheckInvalidConfig' => 'applications/config/check/PhabricatorSetupCheckInvalidConfig.php',
     'PhabricatorSetupCheckMail' => 'applications/config/check/PhabricatorSetupCheckMail.php',
     'PhabricatorSetupCheckMySQL' => 'applications/config/check/PhabricatorSetupCheckMySQL.php',
+    'PhabricatorSetupCheckPath' => 'applications/config/check/PhabricatorSetupCheckPath.php',
     'PhabricatorSetupCheckStorage' => 'applications/config/check/PhabricatorSetupCheckStorage.php',
     'PhabricatorSetupCheckTimezone' => 'applications/config/check/PhabricatorSetupCheckTimezone.php',
     'PhabricatorSetupIssue' => 'applications/config/issue/PhabricatorSetupIssue.php',
@@ -2581,6 +2582,7 @@ phutil_register_library_map(array(
     'PhabricatorSetupCheckInvalidConfig' => 'PhabricatorSetupCheck',
     'PhabricatorSetupCheckMail' => 'PhabricatorSetupCheck',
     'PhabricatorSetupCheckMySQL' => 'PhabricatorSetupCheck',
+    'PhabricatorSetupCheckPath' => 'PhabricatorSetupCheck',
     'PhabricatorSetupCheckStorage' => 'PhabricatorSetupCheck',
     'PhabricatorSetupCheckTimezone' => 'PhabricatorSetupCheck',
     'PhabricatorSetupIssueView' => 'AphrontView',

src/applications/config/check/PhabricatorSetupCheckPath.php

@@ -0,0 +1,30 @@
+<?php
+
+final class PhabricatorSetupCheckPath extends PhabricatorSetupCheck {
+
+  protected function executeChecks() {
+    // NOTE: We've already appended `environment.append-paths`, so we don't
+    // need to explicitly check for it.
+    $path = getenv('PATH');
+
+    if (!$path) {
+      $summary = pht(
+        'The environmental variable $PATH is empty. Phabricator will not '.
+        'be able to execute some commands.');
+
+      $message = pht(
+        'The environmental variable $PATH is empty. Phabricator needs to '.
+        'execute some system commands, like `svn`, `git`, `hg`, and `diff`. '.
+        'To execute these commands, the binaries must be available in the '.
+        'webserver\'s $PATH. You can set additional paths in Phabricator '.
+        'configuration.');
+
+      $this
+        ->newIssue('config.environment.append-paths')
+        ->setName(pht('$PATH Not Set'))
+        ->setSummary($summary)
+        ->setMessage($message)
+        ->addPhabricatorConfig('environment.append-paths');
+    }
+  }
+}

src/infrastructure/PhabricatorSetup.php

@@ -107,26 +107,6 @@ final class PhabricatorSetup {
         "consequences of leaving it unconfigured.\n");
     }
 
-    $path = getenv('PATH');
-    if (empty($path)) {
-      self::writeFailure();
-      self::write(
-        "Setup failure! The environmental \$PATH variable is empty. ".
-        "Phabricator needs to execute system commands like 'svn', 'git', ".
-        "'hg', and 'diff'. Set up your webserver so that it passes a valid ".
-        "\$PATH to the PHP process.\n\n");
-      if (php_sapi_name() == 'fpm-fcgi') {
-        self::write(
-          "You're running php-fpm, so the easiest way to do this is to add ".
-          "this line to your php-fpm.conf:\n\n".
-          "  env[PATH] = /usr/local/bin:/usr/bin:/bin\n\n".
-          "Then restart php-fpm.\n");
-      }
-      return;
-    } else {
-      self::write(" okay  \$PATH is nonempty.\n");
-    }
-
     self::write("[OKAY] Core configuration OKAY.\n");
 
     self::writeHeader("REQUIRED PHP EXTENSIONS");