Proposal: Don't read environment files by default

Richard Eisenberg rae at
Thu Mar 28 13:49:48 UTC 2019

I have spent quite a bit of time debugging this issue, being utterly surprised about the existence of these files. Furthermore, until today, I had been unable to find a way to turn the feature off. I now understand ( that there is an undocumented mechanism for doing so in GHC. It's still frustrating that there is no similar mechanism to globally (i.e., in ~/.cabal/config) disable these files in cabal.

While I expect "project-based" tools to care about their directory (e.g., git, cabal, stack), I would never expect a compiler (which is intended to be a low-level utility) to do so.


> On Mar 28, 2019, at 6:08 AM, Matthew Pickering <matthewtpickering at> wrote:
> Hi all,
> Environment files have caused a large amount of pain for users because
> they are read by default by GHC.
> For example:
> Cabal developers have indicated that they are not going to stop
> generating them by default despite the overwhelming user pressure.
> Therefore I propose that users should opt-in to using environment
> files by having to explicitly pass a flag to enable the search
> behavior.
> This will provide a much better user experience overall and will stop
> tooling having to isolate itself from their existence.
> Cheers,
> Matt
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