On 26/01/14 20:16, Albert Y. C. Lai wrote:
It seems that you are using GHC API. Then your program starts a GHC session, which is not unlike an average ghci session, in particular:
A. It will load and link libraries afresh during run time. This is independent of whatever your executable is linked with.
B. And the default choice of libraries is, clearly: the newest unhidden version.
Therefore, when your GHC session also has to work with compiled code built against older versions, there will be incompatibilities.
Ah, I see.
What do you tell your users?
In my testing, using cabal sandboxes seems to work, but that's not really a full solution.
P.S. cabal-install goes out of its way to dictate library versions to ghc. It begins with -hide-all-packages, then it recites, one by one, -package base-4.1.0.0, -package Cabal-1.16.0, -package text-0.11.3.1,... Are you going to bother to do the same?
I did add some functionality like this recently: https://github.com/carlohamalainen/ghc-imported-from/commit/e1a212000a73372f... (around line 108) which is just using ghc-mod's API to do so. But I still run into the original problem that I had before, at least when not using a sandbox. I'm not sure what to do from here. -- Carlo Hamalainen http://carlo-hamalainen.net