Proposal: Don't read environment files by default

Oleg Grenrus oleg.grenrus at
Thu Mar 28 13:58:07 UTC 2019

There is. Add

    write-ghc-environment-files: never

to your ~/.cabal/config assuming you have cabal-insall- or later.

- Oleg

On 28.3.2019 15.49, Richard Eisenberg wrote:
> 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.
> Richard
>> 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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