Provision_Context_wpplatform not found

[jacobembree]

Drush command terminated abnormally due to an unrecoverable error.Error: Uncaught Error: Class 'Provision_Context_wpplatform' not found in /usr/share/drush/commands/provision/provision.context.inc:132
Stack trace:
#0 /usr/share/drush/commands/provision/provision.context.inc(68): provision_context_factory('@wpplatform_Wor...', true)
 # 1 /usr/share/drush/commands/provision/provision.drush.inc(363): d('@wpplatform_Wor...')
 # 2 phar:///usr/local/bin/drush/includes/command.inc(422): drush_provision_save('@wpplatform_Wor...')
 # 3 phar:///usr/local/bin/drush/includes/command.inc(231): _drush_invoke_hooks(Array, Array)
 # 4 phar:///usr/local/bin/drush/includes/command.inc(199): drush_command('@wpplatform_Wor...')
 # 5 phar:///usr/local/bin/drush/lib/Drush/Boot/BaseBoot.php(67): drush_dispatch(Array)
 # 6 phar:///usr/local/bin/drush/includes/preflight.inc(66): Drush\Boot\BaseBoot->bootstrap_and_dispatch()
 # 7 phar:///usr/local/bin/drush/includes/startup.inc(462): drush_main()
 # 8 phar:///usr/local/bin/drush/includes/startup.inc(369): drush_run_main(false, '/', 'Phar detected. ...')
 # 9 phar:///usr/loc in /usr/share/drush/commands/provision/provision.context.inc, line 132

Provision_Context_wpplatform is in hosting_wpplatform/drush/Provision/Context/wpplatform.php. I don't know how Drush autoloads the classes, though. Mentioning the file in hosting_wpplatform/hosting_wpplatform.info did not help.