作曲家包更新，但不安裝

Question

做

sudo php composer.phar update

後，我得到如下：

Loading composer repositories with package information 
Updating dependencies (including require-dev) 
Installing SOME_PACKAGE (dev-master 6fb0f62) 
Cloning SOME_TOKEN 
Writing lock file Generating autoload filesUpdating 

但是當我做sudo php composer.phar install我得到

Loading composer repositories with package information 
Installing dependencies (including require-dev) from lock file 
Nothing to install or update