When ghc-pkg observes your cache is out of date, it displays a helpful warning, recommending "ghc-pkg recache". However, sometimes running this command does not fix the problem, because it targets the wrong cache.

For out of date global caches, "ghc-pkg --global recache" successfully clears the warning. For out of date user caches, "ghc-pkg --user recache" clears the warning.

In the future, could ghc-pkg display the command more specific to the problem?

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Cheers,

Andrew Pennebaker
www.yellosoft.us