Call to undefined method Wikimedia\Composer\Merge\V2\PluginState::shouldMergeReplace() breaking deployments after upgrade to 2.1

[mlncn]

Our local composer update works fine but the composer install in our deployment process is breaking with that shouldMergeReplace() is undefined error.

Upgrading wikimedia/composer-merge-plugin (v2.0.1 => v2.1.0)

is in the list of changes.

Locking it to 2.0.1 fixes the error. Other changes such as upgrading composer/installers from v1.12.0 to v2.2.0 did not help, though i know when dealing with composer meta things (installers, merge plugin, etc) it can take two cycles of composer, which maybe is why our build process doesn't work, but for now reporting the error because seems no one else has, and our workaround of holding it at 2.0.1.

[mlncn]

Stacktrace output from failed pipeline:

Generating optimized autoload files
In ExtraPackage.php line 175:
                                                                               
  [Error]                                                                      
  Call to undefined method Wikimedia\Composer\Merge\V2\PluginState::shouldMer  
  geReplace()                                                                  
                                                                               
Exception trace:
  at /builds/agaric/sites/mass-design/mass/vendor/wikimedia/composer-merge-plugin/src/ExtraPackage.php:175
 Wikimedia\Composer\Merge\V2\ExtraPackage->mergeInto() at phar:///usr/bin/composer/src/Composer/Plugin/PluginManager.php(274) : eval()'d code:280
 Wikimedia\Composer\Merge\V2\MergePlugin_composer_tmp1->mergeFile() at phar:///usr/bin/composer/src/Composer/Plugin/PluginManager.php(274) : eval()'d code:250
 Wikimedia\Composer\Merge\V2\MergePlugin_composer_tmp1->mergeFiles() at phar:///usr/bin/composer/src/Composer/Plugin/PluginManager.php(274) : eval()'d code:211
 Wikimedia\Composer\Merge\V2\MergePlugin_composer_tmp1->onInstallUpdateOrDump() at phar:///usr/bin/composer/src/Composer/EventDispatcher/EventDispatcher.php:206
 Composer\EventDispatcher\EventDispatcher->doDispatch() at phar:///usr/bin/composer/src/Composer/EventDispatcher/EventDispatcher.php:129
 Composer\EventDispatcher\EventDispatcher->dispatchScript() at phar:///usr/bin/composer/src/Composer/Autoload/AutoloadGenerator.php:189
 Composer\Autoload\AutoloadGenerator->dump() at phar:///usr/bin/composer/src/Composer/Installer.php:349
 Composer\Installer->run() at phar:///usr/bin/composer/src/Composer/Command/InstallCommand.php:146
 Composer\Command\InstallCommand->execute() at phar:///usr/bin/composer/vendor/symfony/console/Command/Command.php:298
 Symfony\Component\Console\Command\Command->run() at phar:///usr/bin/composer/vendor/symfony/console/Application.php:1040
 Symfony\Component\Console\Application->doRunCommand() at phar:///usr/bin/composer/vendor/symfony/console/Application.php:301
 Symfony\Component\Console\Application->doRun() at phar:///usr/bin/composer/src/Composer/Console/Application.php:377
 Composer\Console\Application->doRun() at phar:///usr/bin/composer/vendor/symfony/console/Application.php:171
 Symfony\Component\Console\Application->run() at phar:///usr/bin/composer/src/Composer/Console/Application.php:141
 Composer\Console\Application->run() at phar:///usr/bin/composer/bin/composer:88
 require() at /usr/bin/composer:29

[RishiKulshreshtha]

Facing the exact same issue, subscribing! +1

[jackrabbithanna]

I also get this error.
Did anyone ever solve this?

Generating autoload files
In ExtraPackage.php line 175:
                                                                               
  [Error]                                                                      
  Call to undefined method Wikimedia\Composer\Merge\V2\PluginState::shouldMer
geReplace()                                                                  
                                                                               
Exception trace:
  at /builds/Skvare/thesite/vendor/wikimedia/composer-merge-plugin/src/ExtraPackage.php:175
 Wikimedia\Composer\Merge\V2\ExtraPackage->mergeInto() at phar:///usr/local/bin/composer/src/Composer/Plugin/PluginManager.php(274) : eval()'d code:280
 Wikimedia\Composer\Merge\V2\MergePlugin_composer_tmp2->mergeFile() at phar:///usr/local/bin/composer/src/Composer/Plugin/PluginManager.php(274) : eval()'d code:250
 Wikimedia\Composer\Merge\V2\MergePlugin_composer_tmp2->mergeFiles() at phar:///usr/local/bin/composer/src/Composer/Plugin/PluginManager.php(274) : eval()'d code:211
 Wikimedia\Composer\Merge\V2\MergePlugin_composer_tmp2->onInstallUpdateOrDump() at phar:///usr/local/bin/composer/src/Composer/EventDispatcher/EventDispatcher.php:200
 Composer\EventDispatcher\EventDispatcher->doDispatch() at phar:///usr/local/bin/composer/src/Composer/EventDispatcher/EventDispatcher.php:123
 Composer\EventDispatcher\EventDispatcher->dispatchScript() at phar:///usr/local/bin/composer/src/Composer/Autoload/AutoloadGenerator.php:190
 Composer\Autoload\AutoloadGenerator->dump() at phar:///usr/local/bin/composer/src/Composer/Installer.php:343
 Composer\Installer->run() at phar:///usr/local/bin/composer/src/Composer/Command/InstallCommand.php:144
 Composer\Command\InstallCommand->execute() at phar:///usr/local/bin/composer/vendor/symfony/console/Command/Command.php:298
 Symfony\Component\Console\Command\Command->run() at phar:///usr/local/bin/composer/vendor/symfony/console/Application.php:1028
 Symfony\Component\Console\Application->doRunCommand() at phar:///usr/local/bin/composer/vendor/symfony/console/Application.php:299
 Symfony\Component\Console\Application->doRun() at phar:///usr/local/bin/composer/src/Composer/Console/Application.php:370
 Composer\Console\Application->doRun() at phar:///usr/local/bin/composer/vendor/symfony/console/Application.php:171
 Symfony\Component\Console\Application->run() at phar:///usr/local/bin/composer/src/Composer/Console/Application.php:138
 Composer\Console\Application->run() at phar:///usr/local/bin/composer/bin/composer:88
 require() at /usr/local/bin/composer:29