执行：composer update 时，提示：No valid bower.json was found in any branch or tag of https://github.com/blueimp/JavaScript-Canvas-to-Blob.git, cou ld not load a package from it. 的解决

1、执行：composer update 时，提示：No valid bower.json was found in any branch or tag of https://github.com/blueimp/JavaScript-Canvas-to-Blob.git, cou
ld not load a package from it. 如图1

2、执行：composer global require “fxp/composer-asset-plugin”，更新Composer asset plugin至最新版本，如图2

3、怀疑是蓝灯导致的网络问题，退出蓝灯，如图3

4、再次执行：composer update ，成功，如图4