作曲家不在服务器上更新，需要 php，尽管我已经安装了它

Question

在我的服务器上运行"作曲家更新"时，我收到此错误：

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
    - 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 phpmailer/phpmailer v5.2.7 -> satisfiable by phpmailer/phpmailer[v5.2.7].
    - phpmailer/phpmailer v5.2.7 requires php >=5.0.0 -> no matching package found.
  Problem 4
    - Installation request for gabordemooij/redbean dev-master -> satisfiable by gabordemooij/redbean[dev-master].
    - gabordemooij/redbean dev-master requires php >=5.2.0 -> no matching package found.
  Problem 5
    - Installation request for phpunit/phpunit 3.7.28 -> satisfiable by phpunit/phpunit[3.7.28].
    - phpunit/phpunit 3.7.28 requires php >=5.3.3 -> no matching package found.
  Problem 6
    - Installation request for mikey179/vfsstream v1.2.0 -> satisfiable by mikey179/vfsStream[v1.2.0].
    - mikey179/vfsStream v1.2.0 requires php >=5.3.0 -> no matching package found.
  Problem 7
    - phpunit/phpunit-selenium dev-master requires php >=5.3.3 -> no matching package found.
    - phpunit/phpunit-selenium 1.3.3 requires php >=5.3.3 -> no matching package found.
    - phpunit/phpunit-selenium 1.3.2 requires php >=5.3.3 -> no matching package found.
    - phpunit/phpunit-selenium 1.3.1 requires php >=5.3.3 -> no matching package found.
    - phpunit/phpunit-selenium 1.3.0 requires php >=5.3.3 -> no matching package found.
    - phpunit/phpunit-selenium 1.2.9 requires php >=5.3.3 -> no matching package found.
    - phpunit/phpunit-selenium 1.2.12 requires php >=5.3.3 -> no matching package found.
    - phpunit/phpunit-selenium 1.2.11 requires php >=5.3.3 -> no matching package found.
    - phpunit/phpunit-selenium 1.2.10 requires php >=5.3.3 -> no matching package found.
    - Installation request for phpunit/phpunit-selenium >=1.2 -> satisfiable by phpunit/phpunit-selenium[1.2.10, 1.2.11, 1.2.12, 1.2.9, 1.3.0, 1.3.1, 1.3.2, 1.3.3, dev-master].
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.

它建议我安装 php>=5.3.3，但在服务器上运行 php -v 让我：

PHP 5.4.21 (cli) (built: Oct 28 2013 01:52:12) 
Copyright (c) 1997-2013 The PHP Group
Zend Engine v2.4.0, Copyright (c) 1998-2013 Zend Technologies
    with the ionCube PHP Loader v4.4.1, Copyright (c) 2002-2013, by ionCube Ltd.

这意味着我应该有正确的 php 要求。那么，为什么会出现错误呢？

Answer 1

当我在另一台服务器上遇到这样的问题时，我删除了供应商文件夹并通过SSH删除了composer.lock，然后进行了全新安装。