phpdocumentor/反射

總是報同樣的錯誤，請教如何解決

<code>rd@rd-G31M-ES2C:~/www/laravel-dev$ composer install
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
  - Installing phpdocumentor/reflection-docblock (2.0.4)
    Downloading: Failed       
    Downloading: Failed       
    Downloading: Failed       
    Failed to download phpdocumentor/reflection-docblock from dist: The "https://api.github.com/repos/phpDocumentor/ReflectionDocBlock/zipball/d68dbdc53dc358a816f00b300704702b2eaff7b8" file could not be downloaded: php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution
failed to open stream: php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution
    Now trying to download from source
  - Installing phpdocumentor/reflection-docblock (2.0.4)
    Cloning d68dbdc53dc358a816f00b300704702b2eaff7b8

                                                                                                                         
  [RuntimeException]                                                                                                     
  Failed to clone https://github.com/phpDocumentor/ReflectionDocBlock.git via https, ssh protocols, aborting.            
  - https://github.com/phpDocumentor/ReflectionDocBlock.git                                                              
    Cloning into '/home/rd/www/laravel-dev/vendor/phpdocumentor/reflection-docblock'...                                  
    fatal: unable to access 'https://github.com/phpDocumentor/ReflectionDocBlock.git/': Could not resolve host: github.  
  com                                                                                                                    
  - git@github.com:phpDocumentor/ReflectionDocBlock.git                                                                  
    Cloning into '/home/rd/www/laravel-dev/vendor/phpdocumentor/reflection-docblock'...                                  
    ssh: Could not resolve hostname github.com: Temporary failure in name resolution                                     
    fatal: Could not read from remote repository.                                                                        
                                                                                                                         
    Please make sure you have the correct access rights                                                                  
    and the repository exists. 
</code>

<code>The "https://api.github.com/repos/phpDocumentor/ReflectionDocBlock/zipball/d68dbdc53dc358a816f00b300704702b2eaff7b8" file could not be downloaded: php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution
failed to open stream: php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution
</code>

這個包我瀏覽器可以直接下載下來的，不知道為什麼composer就是死活下不下來