composer "Illegal offset type in isset or empty"报错解决方案

最近更新了composer版本，即执行以下任一命令

composer selfupdate

|

composer self-update

再次执行

composer update -vvv

会出现“Illegal offset type in isset or empty”该错误，临时给出解决方案执行以下命令

composer selfupdate --rollback

原文：http://www.cnblogs.com/fengchi/p/5277568.html