我正在尝试安装bower-asset / nanoscroller软件包，但出现异常
$composer require "bower-asset/nanoscroller:0.7.2"
Could not find package bower-asset/nanoscroller in a version matching 0.7.2
尽管我确实需要该版本
$composer show bower-asset/nanoscroller --all
name : bower-asset/nanoscroller
descrip. : A jQuery plugin that offers a simplistic way of implementing Lion OS scrollbars.
keywords :
versions : dev-master, * 0.8.7, 0.8.6, 0.8.5, 0.8.4, 0.8.3, 0.8.2, 0.8.1, 0.8.0, 0.7.6, 0.7.5, 0.7.4, 0.7.3, 0.7.2, 0.7.1, 0.7, 0.6.9, 0.6.8, 0.6.7, 0.6.6, 0.6.5, 0.6.4, 0.6.3, 0.6.2, 0.6.1, 0.6.0, 0.5.9, 0.5.8, 0.5.7, 0.5.6, dev-feature-horizontal-wip
type : bower-asset-library
source : [git] https://github.com/jamesflorentino/nanoScrollerJS.git b5da5ae4ff0f6a20ed0bfde5c63c95824fc690e6
dist : [zip] https://api.github.com/repos/jamesflorentino/nanoScrollerJS/zipball/b5da5ae4ff0f6a20ed0bfde5c63c95824fc690e6 b5da5ae4ff0f6a20ed0bfde5c63c95824fc690e6
names : bower-asset/nanoscroller
requires
bower-asset/jquery >=1.6
为什么会这样？