安装Yesod Web框架。初始化项目，然后启动它。收到错误：
cabal: The following installed packages are broken because other packages they
depend on are missing. These broken packages must be rebuilt before they can
be used.
package persistent-1.1.5.1 is broken due to missing package
aeson-0.6.2.0-0b5b1be15e07744226b068e794d3d16c
package persistent-postgresql-1.1.3.1 is broken due to missing package
aeson-0.6.2.0-0b5b1be15e07744226b068e794d3d16c
package persistent-template-1.1.3.1 is broken due to missing package
aeson-0.6.2.0-0b5b1be15e07744226b068e794d3d16c
package shakespeare-js-1.1.4.1 is broken due to missing package
aeson-0.6.2.0-0b5b1be15e07744226b068e794d3d16c
package yaml-0.8.5 is broken due to missing package
aeson-0.6.2.0-0b5b1be15e07744226b068e794d3d16c
但是已经安装了aeson-0.6.2软件包：
cabal install aeson-0.6.2
Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: aeson (user goal)
rejecting: aeson-0.6.2.0/installed-353..., 0.6.2.0, 0.6.1.0/installed-23c...,
0.6.1.0, 0.6.0.2, 0.6.0.1, 0.6.0.0, 0.5.0.0, 0.4.0.1, 0.4.0.0, 0.3.2.14,
0.3.2.13, 0.3.2.12, 0.3.2.11, 0.3.2.10, 0.3.2.9, 0.3.2.8, 0.3.2.7, 0.3.2.6,
0.3.2.5, 0.3.2.4, 0.3.2.3, 0.3.2.2, 0.3.2.1, 0.3.2.0, 0.3.1.1, 0.3.1.0,
0.3.0.0, 0.2.0.0, 0.1.0.0 (global constraint requires ==0.6.2)
如何解决此问题？