Error running twig:unused

[rt3me]

Describe the bug
I get an error when I run:

drush twig:unused --field=template /var/www/proect_name/docroot/themes/custom/theme_name

To Reproduce
In local dev environment cd to a Drupal project, execute above command changing path argument as needed to point to a custom theme.

Expected behavior
Expected a list of unused twig templates.

Actual behavior
Drush listed the total number of twig templates found (not unused templates), then output the error:

[notice] Found 247 templates [error] Error: Call to a member function generateKey() on bool in Drush\Drupal\Commands\core\TwigCommands->unused() (line 89 of /var/www/PUB/vendor/drush/drush/src/Drupal/Commands/core/TwigCommands.php) #0 [internal function]: Drush\Drupal\Commands\core\TwigCommands->unused() #1 /var/www/PUB/vendor/consolidation/annotated-command/src/CommandProcessor.php(257): call_user_func_array() #2 /var/www/PUB/vendor/consolidation/annotated-command/src/CommandProcessor.php(212): Consolidation\AnnotatedCommand\CommandProcessor->runCommandCallback() #3 /var/www/PUB/vendor/consolidation/annotated-command/src/CommandProcessor.php(176): Consolidation\AnnotatedCommand\CommandProcessor->validateRunAndAlter() #4 /var/www/PUB/vendor/consolidation/annotated-command/src/AnnotatedCommand.php(350): Consolidation\AnnotatedCommand\CommandProcessor->process() #5 /var/www/PUB/vendor/symfony/console/Command/Command.php(255): Consolidation\AnnotatedCommand\AnnotatedCommand->execute() #6 /var/www/PUB/vendor/symfony/console/Application.php(1027): Symfony\Component\Console\Command\Command->run() #7 /var/www/PUB/vendor/symfony/console/Application.php(273): Symfony\Component\Console\Application->doRunCommand() #8 /var/www/PUB/vendor/symfony/console/Application.php(149): Symfony\Component\Console\Application->doRun() #9 /var/www/PUB/vendor/drush/drush/src/Runtime/Runtime.php(118): Symfony\Component\Console\Application->run() #10 /var/www/PUB/vendor/drush/drush/src/Runtime/Runtime.php(48): Drush\Runtime\Runtime->doRun() #11 /var/www/PUB/vendor/drush/drush/drush.php(72): Drush\Runtime\Runtime->run() #12 /var/www/PUB/vendor/drush/drush/includes/preflight.inc(18): require('/var/www/PUB/ve...') #13 phar:///usr/local/bin/drush/bin/drush.php(143): drush_main() #14 /usr/local/bin/drush(14): require('phar:///usr/loc...') #15 {main}. Error: Call to a member function generateKey() on bool in /var/www/PUB/vendor/drush/drush/src/Drupal/Commands/core/TwigCommands.php on line 89 #0 [internal function]: Drush\Drupal\Commands\core\TwigCommands->unused() #1 /var/www/PUB/vendor/consolidation/annotated-command/src/CommandProcessor.php(257): call_user_func_array() #2 /var/www/PUB/vendor/consolidation/annotated-command/src/CommandProcessor.php(212): Consolidation\AnnotatedCommand\CommandProcessor->runCommandCallback() #3 /var/www/PUB/vendor/consolidation/annotated-command/src/CommandProcessor.php(176): Consolidation\AnnotatedCommand\CommandProcessor->validateRunAndAlter() #4 /var/www/PUB/vendor/consolidation/annotated-command/src/AnnotatedCommand.php(350): Consolidation\AnnotatedCommand\CommandProcessor->process() #5 /var/www/PUB/vendor/symfony/console/Command/Command.php(255): Consolidation\AnnotatedCommand\AnnotatedCommand->execute() #6 /var/www/PUB/vendor/symfony/console/Application.php(1027): Symfony\Component\Console\Command\Command->run() #7 /var/www/PUB/vendor/symfony/console/Application.php(273): Symfony\Component\Console\Application->doRunCommand() #8 /var/www/PUB/vendor/symfony/console/Application.php(149): Symfony\Component\Console\Application->doRun() #9 /var/www/PUB/vendor/drush/drush/src/Runtime/Runtime.php(118): Symfony\Component\Console\Application->run() #10 /var/www/PUB/vendor/drush/drush/src/Runtime/Runtime.php(48): Drush\Runtime\Runtime->doRun() #11 /var/www/PUB/vendor/drush/drush/drush.php(72): Drush\Runtime\Runtime->run() #12 /var/www/PUB/vendor/drush/drush/includes/preflight.inc(18): require('/var/www/PUB/ve...') #13 phar:///usr/local/bin/drush/bin/drush.php(143): drush_main() #14 /usr/local/bin/drush(14): require('phar:///usr/loc...') #15 {main} Error: Call to a member function generateKey() on bool in Drush\Drupal\Commands\core\TwigCommands->unused() (line 89 of /var/www/PUB/vendor/drush/drush/src/Drupal/Commands/core/TwigCommands.php). [warning] Drush command terminated abnormally.

Workaround
No workarounds that I am aware of.

System Configuration

Q	A
Drush version?	10.6.2 (please be specific, and try latest release)
Drupal version?	9.4.5
PHP version	7.4.3
OS?	Ubuntu 20.04

Additional information
Add any other context about the problem here.

[weitzman]

Drush 10 is no longer supported.

[ChrisScrumping]

You need to enable your cache for this command to work.

This error is still shown in Drush 12/13 if the cache is disabled, I created a PR that would hopefully provide a better error.

#5962