So you would like to help improve the error messages we see in the Haskell toolchain and ecosystem?
Welcome! We're glad to have you, and we will do our best to ensure your efforts are worthwhile.
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Serve the Haskell community, focusing on improvements to the error messages seen in the Haskell ecosystem.
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Lower Haskell's barrier-to-entry by increasing the general understanding of the error messages experienced during development.
This project is taking shape, so many details are still being worked out, however:
- Using the issue tracker, this repo will provide a space and workflow for the discussion and collaboration around improving error messages.
- We are interested in building a catalog of error messages for each tool in common use (GHC, Cabal, Stack, ghcup, HLS, etc).
- For each error message that is identified for potential improvement:
- We would like to have a reasonable means of reproducing the error message under different circumstances
- We should identify specific improvements to the messaging
- We will reach out to and work collaboratively with tool developers
- We should document and help improve understanding of the error messaging
- For tools that use error message codes:
- We describe the messages and how to interpret them in the Haskell Message Index (see below)
As a result, this repo may include code that demonstrates the errors we wish to improve, as well as code and material to render documentation relevant to explaining each error and the possible situations the error relates to.
We welcome contributions that help to further progress the project towards its goals.
Contributions may come in the form of changes to the code base, as well as opening or commenting on issues and pull requests.
All contributors are expected to follow the Haskell Foundation's Code of Conduct.
Haskell tooling emits a variety of errors, warnings, and other messages. In an unreleased branch, GHC emits a unique code for each message that allows it to be identified. This site allows these codes to be looked up, providing examples, context, and further information that can make them easier to understand.
Please see CONTRIBUTING.md for instructions on improving the site. Thanks!
The site is built with the Hakyll static site generator. To view the site locally, enter the message-index directory and run:
$ cabal run -- site watch
or
$ stack run -- site watch
which fires up an HTTP server on localhost:8000.
The error messages:
cabal: There is no <pkgname>.cabal package file or cabal.project file. To
build packages locally you need at minimum a <pkgname>.cabal file. You can use
'cabal init' to create one.
For non-trivial projects you will also want a cabal.project file in the root
directory of your project. This file lists the packages in your project and
all other build configuration. See the Cabal user guide for full details.
and
No executables found.
typically indicate that the site was started from the root of the repository, rather than the message-index directory.
The Message Index is a project of the Haskell Foundation. Please get in touch if you have ideas, requests, or any other feedback!