title: Why do I get a version mismatch during composer install for an outdated php version even though correct php version is installed?
body: <p>Given the very base <code>composer.json</code>:</p>
  
  <pre><code>{
    "name": "kopernikus/fizzbuzz",
    "description": "FizzBuzz!",
    "type": "project",
    "require": {
      "php": "^7.0"
    },
    "require-dev": {
      "phpunit/phpunit": "^6.5"
    },
    "license": "MIT",
    "authors": [
      {
        "name": "Philipp Kretzschmar",
        "email": "philipp.kretzschmar@gmail.com"
      }
    ]
  }
  </code></pre>
  
  <p>If I run:</p>
  
  <pre><code>$ composer install
  </code></pre>
  
  <p>I get:</p>
  
  <pre><code>Loading composer repositories with package information
  Updating dependencies (including require-dev)
  Your requirements could not be resolved to an installable set of packages.
  
    Problem 1
      - This package requires php ^7.0 but your PHP version (5.5) does not satisfy that requirement.
    Problem 2
      - phpunit/phpunit 5.7.9 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.8 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.7 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.6 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.5 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.4 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.3 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.26 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.25 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.24 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.23 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.22 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.21 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.20 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.2 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.19 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.18 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.17 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.16 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.15 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.14 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.13 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.12 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.11 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.10 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.1 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.7.0 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.6.8 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.6.7 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.6.6 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.6.5 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.6.4 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.6.3 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.6.2 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.6.1 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.6.0 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.5.7 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.5.6 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.5.5 requires ext-mbstring * -&gt; the requested PHP extension mbstring is missing from your system.
      - phpunit/phpunit 5.5.4 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.5.3 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.5.2 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.5.1 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.5.0 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.4.8 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.4.7 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.4.6 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.4.5 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.4.4 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.4.3 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.4.2 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.4.1 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.4.0 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.3.5 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.3.4 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.3.3 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.3.2 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.3.1 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.3.0 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.2.9 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.2.8 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.2.7 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.2.6 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.2.5 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.2.4 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.2.3 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.2.2 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.2.12 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.2.11 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.2.10 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.2.1 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.2.0 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.1.7 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.1.6 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.1.5 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.1.4 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.1.3 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.1.2 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.1.1 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.1.0 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.0.9 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.0.8 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.0.7 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.0.6 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.0.5 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.0.4 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.0.3 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.0.2 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.0.10 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.0.1 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.0.0 requires php &gt;=5.6 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - phpunit/phpunit 5.5.4 requires php ^5.6 || ^7.0 -&gt; your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.
      - Installation request for phpunit/phpunit ^5 -&gt; satisfiable by phpunit/phpunit[5.0.0, 5.0.1, 5.0.10, 5.0.2, 5.0.3, 5.0.4, 5.0.5, 5.0.6, 5.0.7, 5.0.8, 5.0.9, 5.1.0, 5.1.1, 5.1.2, 5.1.3, 5.1.4, 5.1.5, 5.1.6, 5.1.7, 5.2.0, 5.2.1, 5.2.10, 5.2.11, 5.2.12, 5.2.2, 5.2.3, 5.2.4, 5.2.5, 5.2.6, 5.2.7, 5.2.8, 5.2.9, 5.3.0, 5.3.1, 5.3.2, 5.3.3, 5.3.4, 5.3.5, 5.4.0, 5.4.1, 5.4.2, 5.4.3, 5.4.4, 5.4.5, 5.4.6, 5.4.7, 5.4.8, 5.5.0, 5.5.1, 5.5.2, 5.5.3, 5.5.4, 5.5.5, 5.5.6, 5.5.7, 5.6.0, 5.6.1, 5.6.2, 5.6.3, 5.6.4, 5.6.5, 5.6.6, 5.6.7, 5.6.8, 5.7.0, 5.7.1, 5.7.10, 5.7.11, 5.7.12, 5.7.13, 5.7.14, 5.7.15, 5.7.16, 5.7.17, 5.7.18, 5.7.19, 5.7.2, 5.7.20, 5.7.21, 5.7.22, 5.7.23, 5.7.24, 5.7.25, 5.7.26, 5.7.3, 5.7.4, 5.7.5, 5.7.6, 5.7.7, 5.7.8, 5.7.9].
  
    To enable extensions, verify that they are enabled in your .ini files:
      - /etc/php/7.0/cli/php.ini
      - /etc/php/7.0/cli/conf.d/10-mysqlnd.ini
      - /etc/php/7.0/cli/conf.d/10-opcache.ini
      - /etc/php/7.0/cli/conf.d/10-pdo.ini
      - /etc/php/7.0/cli/conf.d/15-xml.ini
      - /etc/php/7.0/cli/conf.d/20-apcu.ini
      - /etc/php/7.0/cli/conf.d/20-apcu_bc.ini
      - /etc/php/7.0/cli/conf.d/20-calendar.ini
      - /etc/php/7.0/cli/conf.d/20-ctype.ini
      - /etc/php/7.0/cli/conf.d/20-curl.ini
      - /etc/php/7.0/cli/conf.d/20-dom.ini
      - /etc/php/7.0/cli/conf.d/20-exif.ini
      - /etc/php/7.0/cli/conf.d/20-fileinfo.ini
      - /etc/php/7.0/cli/conf.d/20-ftp.ini
      - /etc/php/7.0/cli/conf.d/20-gettext.ini
      - /etc/php/7.0/cli/conf.d/20-iconv.ini
      - /etc/php/7.0/cli/conf.d/20-intl.ini
      - /etc/php/7.0/cli/conf.d/20-json.ini
      - /etc/php/7.0/cli/conf.d/20-mongodb.ini
      - /etc/php/7.0/cli/conf.d/20-mysqli.ini
      - /etc/php/7.0/cli/conf.d/20-pdo_mysql.ini
      - /etc/php/7.0/cli/conf.d/20-phar.ini
      - /etc/php/7.0/cli/conf.d/20-posix.ini
      - /etc/php/7.0/cli/conf.d/20-readline.ini
      - /etc/php/7.0/cli/conf.d/20-shmop.ini
      - /etc/php/7.0/cli/conf.d/20-simplexml.ini
      - /etc/php/7.0/cli/conf.d/20-sockets.ini
      - /etc/php/7.0/cli/conf.d/20-sysvmsg.ini
      - /etc/php/7.0/cli/conf.d/20-sysvsem.ini
      - /etc/php/7.0/cli/conf.d/20-sysvshm.ini
      - /etc/php/7.0/cli/conf.d/20-tokenizer.ini
      - /etc/php/7.0/cli/conf.d/20-wddx.ini
      - /etc/php/7.0/cli/conf.d/20-xmlreader.ini
      - /etc/php/7.0/cli/conf.d/20-xmlwriter.ini
      - /etc/php/7.0/cli/conf.d/20-xsl.ini
  </code></pre>
  
  <p>I am highley confused since:</p>
  
  <pre><code>php -v
  PHP 7.0.26-2+ubuntu16.04.1+deb.sury.org+2 (cli) (built: Dec  7 2017 20:09:40) ( NTS )
  Copyright (c) 1997-2017 The PHP Group
  Zend Engine v3.0.0, Copyright (c) 1998-2017 Zend Technologies
      with Zend OPcache v7.0.26-2+ubuntu16.04.1+deb.sury.org+2, Copyright (c) 1999-2017, by Zend Technologies
  </code></pre>
  
  <p>I also checked the composer script, it has defined:</p>
  
  <pre><code>$ which composer
  /usr/local/bin/composer
  
  $ head -n 1 /usr/local/bin/composer
  #!/usr/bin/env php
  
  $ /usr/bin/env php
  PHP 7.0.26-2+ubuntu16.04.1+deb.sury.org+2 (cli) (built: Dec  7 2017 20:09:40) ( NTS )
  Copyright (c) 1997-2017 The PHP Group
  Zend Engine v3.0.0, Copyright (c) 1998-2017 Zend Technologies
      with Zend OPcache v7.0.26-2+ubuntu16.04.1+deb.sury.org+2, Copyright (c) 1999-2017, by Zend Technologies
  </code></pre>
  
  <p>Even <code>diagnose</code> gives no cause to alarm:</p>
  
  <pre><code>$ composer diagnose
  Checking composer.json: OK
  Checking platform settings: OK
  Checking git settings: OK
  Checking http connectivity to packagist: OK
  Checking https connectivity to packagist: OK
  Checking github.com rate limit: OK
  Checking disk free space: OK
  Checking pubkeys: 
  Tags Public Key Fingerprint: 57815BA2 7E54DC31 7ECC7CC5 573090D0  87719BA6 8F3BB723 4E5D42D0 84A14642
  Dev Public Key Fingerprint: 4AC45767 E5EC2265 2F0C1167 CBBB8A2B  0C708369 153E328C AD90147D AFE50952
  OK
  Checking composer version: OK
  Composer version: 1.6.1
  PHP version: 7.0.26-2+ubuntu16.04.1+deb.sury.org+2
  PHP binary path: /usr/bin/php7.0
  </code></pre>
  
  <p>Why does composer think I am running php@5.5 even though I only have php@7 installed?</p>