id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,os,architecture,failure,difficulty,testcase,blockedby,blocking,related
4103,report location of global package db in ghc --info,duncan,simonmar,"Cabal does a sanity check to make sure it has a ghc and ghc-pkg program that are the same version. This is sometimes not enough.

In #haskell today we had a case where there was `/usr/bin/ghc` and `/usr/local/bin/ghc-pkg`. This gave rise to pretty weird behaviour that was hard to track down. Packages could be built, but when they were installed they always appeared to be broken, missing a dependency on base.

We could improve Cabal's sanity check if it checked that `ghc` and `ghc-pkg` agreed on the location of the global package database. That would seem to be the canonical check that the two belong to a single instance of a ghc installation.

To be able to perform this check, it would be useful to extend ghc's `--info` flag to include the location of the global package db.",feature request,closed,normal,,Compiler,6.12.2,fixed,,,Unknown/Multiple,Unknown/Multiple,None/Unknown,,,,,