Reenable doctests

[sjoerdvisscher]

Cabal 3.4.0.0 is out now, so I reenabled the doctest.

But most the doctests are failing with an error like:

attempting to use module ‘main:Foreign.Marshal.Pure’ (...) which is not loaded

@utdemir Do you know what might cause this?

[utdemir]

@utdemir Do you know what might cause this?

@sjoerdvisscher Unfortunately, I don't remember seeing that error with cabal-doctests before, I just had a quick look and couldn't solve it easily.

One interesting thing to note is that, only some of the doctests fail, eg. the test in Data/Array/Mutable/Linear.hs seems to be fine. My guess is that it's something about the dependency order, where importing something from above the dependency chain in a test fails. This might be the reason of tests in Data.V.Linear failing to import Prelude.Linear, but this is not the case Data.Array.Mutable.Linear (which is not a dependency of Prelude.Linear).

So, when I built the linear-base and passed the package to doctests, it works (after fixing one legitimate test failure):

$ cabal build
$ cabal exec -- doctest -package linear-base src/**/*.hs

However, I don't have any opinion on how we can fix it.

[andreabedini]

I am looking at this and FWIW, I seem to be able to succesfully run the doctests in the configured nix shell using cabal-docspec, just as Oleg suggests in the issue linked above.

In that issue Oleg says

But cabal-docspec doesn't work with stack nor Nix(pkgs) based setup, so it's probably not an option for you.

I am not sure what this means. Given the current setup, I belive the only missing bit is including cabal-docspec in the nix shell.

[andreabedini]

Closing in favour of #361