Added link to composer.org docs on ProcessTimedOutException (#9796)

src/Composer/Console/Application.php

@@ -33,6 +33,7 @@ use Composer\Util\ErrorHandler;
 use Composer\Util\HttpDownloader;
 use Composer\EventDispatcher\ScriptExecutionException;
 use Composer\Exception\NoSslException;
+use Symfony\Component\Process\Exception\ProcessTimedOutException;
 
 /**
  * The console application that handles the commands
@@ -385,6 +386,11 @@ class Application extends BaseApplication
             $io->writeError('<error>Check https://getcomposer.org/doc/articles/troubleshooting.md#proc-open-fork-failed-errors for details</error>', true, IOInterface::QUIET);
         }
 
+        if ($exception instanceof ProcessTimedOutException) {
+            $io->writeError('<error>The following exception is caused by a process timeout</error>', true, IOInterface::QUIET);
+            $io->writeError('<error>Check https://getcomposer.org/doc/06-config.md#process-timeout for details</error>', true, IOInterface::QUIET);
+        }
+
         if ($hints = HttpDownloader::getExceptionHints($exception)) {
             foreach ($hints as $hint) {
                 $io->writeError($hint, true, IOInterface::QUIET);

src/Composer/Util/ProcessExecutor.php

@@ -367,11 +367,17 @@ class ProcessExecutor
         }
     }
 
+    /**
+     * @return int the timeout in seconds
+     */
     public static function getTimeout()
     {
         return static::$timeout;
     }
 
+    /**
+     * @param int $timeout the timeout in seconds
+     */
     public static function setTimeout($timeout)
     {
         static::$timeout = $timeout;