laravel4.2安装不成功

[xugege]

我使用laravel4.2，但是通过composer安装的时候不能成功
[RuntimeException]
Could not load package intervention/image in http://packagist.phpcomposer.c
om: [UnexpectedValueException] Could not parse version constraint 4.x.x: In
valid version string "4.x.x"

Could not parse version constraint 4.x.x: Invalid version string "4.x.x"

[overtrue]

明明报的是 intervention/image 包的版本号写得不对，与我这个包没有任何关系，麻烦报错时读一下错误消息，谢谢。