Servant Client Query

I am getting this error: No instance for (Show (ClientM Bittrex)) arising from a use of ‘print While building the following code: {-# LANGUAGE DataKinds #-} {-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE TypeOperators #-} module Main where impo...
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2017-10-03 19:10 (0) Answers

Installing a package outside current resolver

I'm using stack lts-9.0 snapshot, which includes process-1.4.X. Due to some problems with this version, I would like to use process-1.6.1.0. Adding this version to extra-deps does not seem to be enough: extra-deps: - process-1.6.1.0 since this wil...
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2017-10-02 11:10 (1) Answers

How to prevent Stack from creating .dump-hi files?

By default, stack build creates a a directory of .dump-hi files in .stack-work. In my program, the largest of these files takes 1.9 GB. (Its corresponding .hi files takes only 24 MB.) As far as I understand, these files are totally unnecessary, and ...
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2017-09-25 06:09 (1) Answers

multicore parallelism with stack runghc

I had been working on a script in which I hoped to take advantage of multiple processors in my machine by swapping out mapM with Async.mapConcurrently. Observing no speed increase in that instance, I wanted to verify that runghc can indeed utilize m...
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2017-09-20 02:09 (1) Answers

Custom snapshots with stack 1.5.1

I upgraded to stack-1.5.1 from stack-1.4.0, and suddenly it started to refuse my stack.yaml with custom snapshot. Here's the beginning of the stack.yaml: resolver: name: integer-simple-snapshot location: deps/flaw/integer-simple-snapshot.yaml ....
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2017-09-19 00:09 (1) Answers

I cant import System.Directory when using stack

I am little confused about why this doesn't work. I have a small program that import System.Directory. When I run it with runhaskell on the command line it compiles and outputs what I expect. When I use the same program with stack I get a message s...
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2017-09-17 05:09 (1) Answers

Sharing ~/.stack with docker

Our team is using Docker for building our Haskell app in it, and in order to optimize build times, we work towards sharing the ~/.stack directory from OS with the one inside docker containers. Initial implementation was to just reuse the one from OS,...
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2017-09-05 15:09 (0) Answers

How to rasterize SVG to SDL.Surface in Haskell?

I'm using sdl2@2.2.0 and sdl2-image@2.0.0. I'd like to draw a SVG image, but sdl2-image doesn't support this format (see https://www.libsdl.org/projects/SDL_image/): SDL_image is an image file loading library. It loads images as SDL surfaces an...
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2017-08-29 08:08 (1) Answers

Given Cooridnates of Map

type Coordinate = (XCoord, YCoord) type XCoord = Coord type YCoord = Coord type Coord = Integer coordInBound :: Coordinate -> Bool coordInBound (XCoord, YCoord) = XCoord |x >= 0 && x <= 9 = True |otherwise = False...
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2017-08-28 05:08 (2) Answers

Haskell Stack Setup - Can't Recognize CPP Program

I am following the Udemy Haskell course, which at one point I'm shown to download Haskell using the Stack option. I've configured my $PATH and ran stack setup when I run into an issue. configure: WARNING: configure can't recognize your CPP program, ...
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2017-08-21 14:08 (1) Answers

Build haskell stack tests without running

I've made a very simple project with a failing test suite https://github.com/k-bx/noruntests-play Now when I run stack --test --no-run-tests build I would expect it to build the project, but not run the tests. Instead, it runs the tests: ➜ norun...
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2017-08-18 19:08 (1) Answers

How to install d3js Haskell package?

I'd just like to try the Haskell d3js package. Here's what I tried: stack install d3js But it gives the error: Error: While constructing the build plan, the following exceptions were encountered: In the dependencies for d3js-0.1.0.0: base-...
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2017-08-15 17:08 (2) Answers

intero-goto-definition doesn't include libraries?

I am trying to use M-. to go to the definition of a function, but it seems like intero-goto-definition only works the library I am currently developing, not on ones that I am importing. Here is my stack.yaml: flags: {} extra-package-dbs: [] package...
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2017-08-11 21:08 (1) Answers

Stack test output garbled on MINGW64

I'm running GHC using Stack on Windows 10, and using Git Bash (MINGW64) for much of my daily workflow. That includes using GHC and GHCi, which generally works fine. However, when I run stack test from MINGW64, the output is garbled by ANSI color cod...
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2017-08-10 10:08 (1) Answers