This is how composer tells you you have wrong PHP verison

gistfile1.txt

[vagrant@ezp5 ezpublish5]$ composer.phar install --prefer-dist
Loading composer repositories with package information
Installing dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - The requested package php could not be found in any version, there may be a typo in the package name.
  Problem 2
    - The requested package php could not be found in any version, there may be a typo in the package name.
  Problem 3
    - Installation request for symfony/assetic-bundle 2.3.* -> satisfiable by symfony/assetic-bundle[v2.3.0].
    - symfony/assetic-bundle v2.3.0 requires php >=5.3.0 -> no matching package found.
  Problem 4
    - Installation request for symfony/monolog-bundle 2.3.* -> satisfiable by symfony/monolog-bundle[v2.3.0].
    - symfony/monolog-bundle v2.3.0 requires php >=5.3.2 -> no matching package found.
  Problem 5
    - Installation request for tedivm/stash-bundle 0.4.* -> satisfiable by tedivm/stash-bundle[v0.4.1].
    - tedivm/stash-bundle v0.4.1 requires php >=5.3.0 -> no matching package found.
  Problem 6
    - Installation request for whiteoctober/breadcrumbs-bundle ~1.0.1 -> satisfiable by whiteoctober/breadcrumbs-bundle[1.0.1].
    - whiteoctober/breadcrumbs-bundle 1.0.1 requires php >=5.3.2 -> no matching package found.
  Problem 7
    - Installation request for hautelook/templated-uri-bundle ~1.0 -> satisfiable by hautelook/templated-uri-bundle[1.0.0].
    - hautelook/templated-uri-bundle 1.0.0 requires php >=5.3.0 -> no matching package found.
  Problem 8
    - Installation request for doctrine/doctrine-bundle ~1.3@beta -> satisfiable by doctrine/doctrine-bundle[v1.3.0-beta1].
    - doctrine/doctrine-bundle v1.3.0-beta1 requires php >=5.3.2 -> no matching package found.
  Problem 9
    - Installation request for behat/sahi-client dev-master as 1.1.1 -> satisfiable by behat/sahi-client[dev-master].
    - behat/sahi-client dev-master requires php >=5.3.1 -> no matching package found.
  Problem 10
    - Installation request for ezsystems/behatbundle @dev -> satisfiable by ezsystems/behatbundle[dev-master].
    - ezsystems/behatbundle dev-master requires php >=5.3.3 -> no matching package found.
  Problem 11
    - ezsystems/demobundle v5.3.2-rc1 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle v5.3.1-rc1 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle v5.3.0-rc2 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle v5.3.0 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle v5.2.1 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle v5.2.0 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle v2014.05.0 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle v2014.03.1 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle v2014.01.1 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle v2014.01.0 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle v2013.11.0 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle v2013.09.1 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle v2013.09.0 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle dev-stable-5.3 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle dev-stable-5.2 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle dev-stable-5.1 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle dev-sql-ng-hacking requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle dev-master requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle dev-ezp-22627-place_listing_languages requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle dev-ezp-20509_cache_issue requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle dev-bdd/website_toolbar requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle 5.2.0-BETA1 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle 5.1.1 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle 5.1.0-RC1 requires php >=5.3.3 -> no matching package found.
    - ezsystems/demobundle 5.1.0 requires php >=5.3.3 -> no matching package found.
    - Installation request for ezsystems/demobundle @dev -> satisfiable by ezsystems/demobundle[5.1.0, 5.1.0-RC1, 5.1.1, 5.2.0-BETA1, dev-bdd/website_toolbar, dev-ezp-20509_cache_issue, dev-ezp-22627-place_listing_languages, dev-master, dev-sql-ng-hacking, dev-stable-5.1, dev-stable-5.2, dev-stable-5.3, v2013.09.0, v2013.09.1, v2013.11.0, v2014.01.0, v2014.01.1, v2014.03.1, v2014.05.0, v5.2.0, v5.2.1, v5.3.0, v5.3.0-rc2, v5.3.1-rc1, v5.3.2-rc1].

Potential causes:
 - A typo in the package name
 - The package is not available in a stable-enough version according to your minimum-stability setting
   see <https://groups.google.com/d/topic/composer-dev/_g3ASeIFlrc/discussion> for more details.

Read <http://getcomposer.org/doc/articles/troubleshooting.md> for further common problems.

anything less would be too subtle? :-D