title: composer require hangs and then returns KILLED
body: <p>I'm trying to simply install a package to my project by running</p>
  
  <pre><code>composer clearcache
  php -d memory_limit=8G /usr/local/bin/composer require ratchet/pawl -vvv
  </code></pre>
  
  <p>So it starts the process and then gets killed at same point everytime.</p>
  
  <pre><code>Reading ./composer.json
  Loading auth config from COMPOSER_AUTH
  Loading config file ./composer.json
  Checked CA file /etc/ssl/certs/ca-certificates.crt: valid
  Executing command (/var/www): git branch --no-color --no-abbrev -v
  Failed to initialize global composer: Composer could not find the config file: /root/.composer/composer.json
  To initialize a project, please create a composer.json file as described in the https://getcomposer.org/ "Getting Started" section
  Reading /var/www/vendor/composer/installed.json
  Loading plugin UpdateHelper\ComposerPlugin
  Running 1.8.4 (2019-02-11 10:52:10) with PHP 7.2.21-1+ubuntu16.04.1+deb.sury.org+1 on Linux / 4.9.184-linuxkit
  Do not run Composer as root/super user! See https://getcomposer.org/root for details
  Downloading https://repo.packagist.org/packages.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/packages.json into cache
  Downloading http://repo.packagist.org/p/provider-2013%240203c4461d002a56aecb25720bc47e6f0bcdfce9f6818a12999ff76c9a4da3a2.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/p-provider-2013.json into cache
  Downloading http://repo.packagist.org/p/provider-2014%24b82278e95f26c26eef8ced3419716f0a3ff63567ce53f00710ace8efa4c78324.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/p-provider-2014.json into cache
  Downloading http://repo.packagist.org/p/provider-2015%24b99c9cc56fe9d03e7c3c12e9a2447907d6e52b3da50a6081731f12e444fce188.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/p-provider-2015.json into cache
  Downloading http://repo.packagist.org/p/provider-2016%247f1b9d2d1146db402214737b3ed21b449086cc8d3c7ad38a2b22567ade4617e7.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/p-provider-2016.json into cache
  Writing /root/.composer/cache/repo/https---repo.packagist.org/p-provider-2019-10.json into cache
  Downloading http://repo.packagist.org/p/provider-archived%24f87c6b240bff8b508c75240fba1a80bd37b4e866f18cfcad053e9dec578da551.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/p-provider-archived.json into cache
  Downloading http://repo.packagist.org/p/provider-latest%24b0c4bb303105ccc995be5ccf0ea6769bcba9a6e094619cd8a7ae73e1986c28c7.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/p-provider-latest.json into cache
  Downloading http://repo.packagist.org/p/ratchet/pawl%2462f69f5d787999eceae6b525667b7b8ff6f9bc593360c5983cdd8af26050cefa.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/provider-ratchet$pawl.json into cache
  Using version ^0.3.4 for ratchet/pawl
  ./composer.json has been updated
  Reading ./composer.json
  Loading auth config from COMPOSER_AUTH
  Loading config file ./composer.json
  Executing command (/var/www): git branch --no-color --no-abbrev -v
  Failed to initialize global composer: Composer could not find the config file: /root/.composer/composer.json
  To initialize a project, please create a composer.json file as described in the https://getcomposer.org/ "Getting Started" section
  Reading /var/www/vendor/composer/installed.json
  Loading plugin UpdateHelper\ComposerPlugin_composer_tmp0
  Reading ./composer.lock
  Loading composer repositories with package information
  Downloading https://repo.packagist.org/packages.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/packages.json into cache
  Updating dependencies (including require-dev)
  Reading /root/.composer/cache/repo/https---repo.packagist.org/p-provider-2013.json from cache
  Reading /root/.composer/cache/repo/https---repo.packagist.org/p-provider-2014.json from cache
  Reading /root/.composer/cache/repo/https---repo.packagist.org/p-provider-2015.json from cache
  Reading /root/.composer/cache/repo/https---repo.packagist.org/p-provider-2016.json from cache
  Reading /root/.composer/cache/repo/https---repo.packagist.org/p-provider-2019-10.json from cache
  Reading /root/.composer/cache/repo/https---repo.packagist.org/p-provider-archived.json from cache
  Reading /root/.composer/cache/repo/https---repo.packagist.org/p-provider-latest.json from cache
  Downloading http://repo.packagist.org/p/illuminate/support%24d652f6bdd78a3036b4f9e9302354d5ddcab5253f63e28755ab9180a900e95665.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/provider-illuminate$support.json into cache
  Downloading http://repo.packagist.org/p/anlutro/l4-settings%246167169a90d59368f1170c7c3e4115a0e78c1f94dafe9461064da8a4a4794e06.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/provider-anlutro$l4-settings.json into cache
  Downloading http://repo.packagist.org/p/illuminate/contracts%24990d3ec0e17f2b12b5c010f5059ca7fed1c64dbf5547e75f6131736756b10fdc.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/provider-illuminate$contracts.json into cache
  Downloading http://repo.packagist.org/p/doctrine/inflector%241a430d4a3e775fbcbb4e1b52cfc1706889cc7c2d89241ed35df643dc429c7489.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/provider-doctrine$inflector.json into cache
  Downloading http://repo.packagist.org/p/danielstjules/stringy%24bec2231169c19709770f0c453519d68180e141040c955df3ff2bc214a9771e87.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/provider-danielstjules$stringy.json into cache
  Downloading http://repo.packagist.org/p/paragonie/random_compat%2468ff27aa219fec8d8247d50154f1bd6c7810d4277451489674746feef93e444c.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/provider-paragonie$random-compat.json into cache
  Downloading http://repo.packagist.org/p/nesbot/carbon%24f0a91af0b70ce623965325f42ec686d927b5bea003c47c9f9ee430f5756f152c.json
  Downloading http://repo.packagist.org/p/php-di/php-di%24a0c467779053eec738f8479a2d0acc3725634d1cf6cb38760249b71dc10b1632.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/provider-php-di$php-di.json into cache
  Downloading http://repo.packagist.org/p/container-interop/container-interop%2430ca292e11273ec85c024d14c4ca08da2d60afebdac962706d563dab219dad96.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/provider-container-interop$container-interop.json into cache
  Downloading http://repo.packagist.org/p/php-di/invoker%24936f98da50a8458e6d9120382a94990bb20d93481dbcea7cc9ce6146f0c5b1b2.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/provider-php-di$invoker.json into cache
  Downloading http://repo.packagist.org/p/php-di/phpdoc-reader%24de8acf931743484b7918c48fb67f79f97c00c393bef11cbb830765e18b5c5471.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/provider-php-di$phpdoc-reader.json into cache
  Downloading http://repo.packagist.org/p/phpunit/phpunit-mock-objects%24ef9a590beb4bd7770199fab9b41e09273ea9ed85c8ca363dd7b648bba96feef0.json
  Writing /root/.composer/cache/repo/https---repo.packagist.org/provider-phpunit$phpunit-mock-objects.json into cache
  Killed
  root@f23dff79c68e:/var/www#
  </code></pre>
  
  <p>My current <code>composer.json</code> file is</p>
  
  <pre><code>{
      "name": "laravel/laravel",
      "description": "The Laravel Framework.",
      "keywords": ["framework", "laravel"],
      "license": "MIT",
      "type": "project",
      "require": {
          "php": "^7.1.3",
          "anlutro/l4-settings": "^0.7.3",
          "bensampo/laravel-enum": "^1.11",
          "berkayk/onesignal-laravel": "^1.0",
          "beyondcode/laravel-websockets": "^1.3",
          "chapeupreto/sinesp": "^1.5",
          "crockett/csv-seeder": "^1.1",
          "cviebrock/eloquent-sluggable": "^4.5",
          "fideloper/proxy": "^4.0",
          "guzzlehttp/guzzle": "^6.3",
          "kreait/firebase-php": "^4.0",
          "laravel/framework": "5.7.*",
          "laravel/tinker": "^1.0",
          "league/flysystem-aws-s3-v3": "^1.0",
          "malhal/laravel-geographical": "^1.0",
          "noh4ck/graphiql": "^1.0",
          "phpseclib/phpseclib": "2.0",
          "ratchet/pawl": "^0.3.4",
          "rebing/graphql-laravel": "^1.14",
          "s-ichikawa/laravel-sendgrid-driver": "^2.0",
          "simplesoftwareio/simple-qrcode": "^2.0",
          "spatie/laravel-tags": "^2.0",
          "tightenco/ziggy": "^0.6.7",
          "total-voice/php-client": "1.*",
          "tucker-eric/eloquentfilter": "^1.4",
          "tymon/jwt-auth": "1.0.0-rc.3",
          "zizaco/entrust": "^1.9"
      },
      "require-dev": {
          "filp/whoops": "^2.0",
          "fzaninotto/faker": "^1.4",
          "mockery/mockery": "^1.0",
          "nunomaduro/collision": "^2.0",
          "phpunit/phpunit": "^7.0"
      },
      "autoload": {
          "classmap": [
              "database/seeds",
              "database/factories"
          ],
          "psr-4": {
              "App\\": "app/"
          }
      },
      "autoload-dev": {
          "psr-4": {
              "Tests\\": "tests/"
          }
      },
      "extra": {
          "laravel": {
              "dont-discover": [
              ]
          }
      },
      "scripts": {
          "post-root-package-install": [
              "@php -r \"file_exists('.env') || copy('.env.example', '.env');\""
          ],
          "post-create-project-cmd": [
              "@php artisan key:generate"
          ],
          "post-autoload-dump": [
              "Illuminate\\Foundation\\ComposerScripts::postAutoloadDump",
              "@php artisan package:discover"
          ]
      },
      "config": {
          "preferred-install": "dist",
          "sort-packages": true,
          "optimize-autoloader": true
      },
      "minimum-stability": "dev",
      "prefer-stable": true
  }
  </code></pre>
  
  <p>I'm using MacOS and Docker (Laradock).</p>
  
  <p>Also, I've already tried to clear compose cache and add memory to composer command.</p>
  
  <p>Am I doing something wrong?</p>