Error due to conflicting global (1.3.1) and project (1.4.0) version

[schmunk42]

I have 1.3.1 installed globally and no require in my project.

While update runs fine, I noticed that in my composer.lock I get "forcibly" injected version 1.4.0 of this plugin. When running composer show it shows the the plugin, but composer why ... claims the package is unknown.

When running install I get this error:

[Symfony\Component\Debug\Exception\FatalThrowableError]                         
  Call to undefined method Wikimedia\Composer\Merge\ExtraPackage::mergeDevInto()

---

My current workaround is to limit installations to 1.3 in my root composer.json

    "require": {
        "wikimedia/composer-merge-plugin": "~1.3.1"
    },

Does the plugin needs to inject itself at all? If so, I think it would be better to inject its current version.

[schmunk42]

Stacktrace:

Fatal error: Uncaught Error: Call to undefined method Wikimedia\Composer\Merge\PluginState::shouldMergeDev() in phar:///opt/bin/composer.phar/src/Composer/Plugin/PluginManager.php(194) : eval()'d code:300
Stack trace:
#0 [internal function]: Wikimedia\Composer\MergePlugin_composer_tmp2->onDependencySolve(Object(Composer\Installer\InstallerEvent))
#1 phar:///opt/bin/composer.phar/src/Composer/EventDispatcher/EventDispatcher.php(170): call_user_func(Array, Object(Composer\Installer\InstallerEvent))
#2 phar:///opt/bin/composer.phar/src/Composer/EventDispatcher/EventDispatcher.php(134): Composer\EventDispatcher\EventDispatcher->doDispatch(Object(Composer\Installer\InstallerEvent))
#3 phar:///opt/bin/composer.phar/src/Composer/Installer.php(458): Composer\EventDispatcher\EventDispatcher->dispatchInstallerEvent('pre-dependencie...', true, Object(Composer\DependencyResolver\DefaultPolicy), Object(Composer\DependencyResolver\Pool), Object(Composer\Repository\CompositeRepository), Object(Composer\DependencyResolver\Request))
#4 ph in phar:///opt/bin/composer.phar/src/Composer/Plugin/PluginManager.php(194) : eval()'d code on line 300

[bd808]

Global installation is not a considered or expected use case. Composer-merge-plugin is intended to be used cooperatively with the root composer.json for any particular deployment. What is your expected behavior with the plugin installed globally?

[schmunk42]

Because we're using it in most of our projects we added it to our development environment (Docker images). We're usually working with build tools from this image, including composer. Some other plugins only work in global mode, I just did not saw anything stating that you should not do this :) I also thought it would save one run of dependency resolution, if it is already there.

So, maybe something worth adding to the docs... or disallow global installation or throw a warning.