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+# Contributing to Haddock
+
+Thank you for contributing to Haddock! Here is the information you will need in
+order to make your contribution
+
+## Reporting issues
+
+Please open a ticket if you get an unexpected behaviour from Haddock!  
+You should ideally include a [Short, Self Contained, Correct (Compilable), Example][SSCCE]
+in your ticket, so that the maintainers may easily reproduce your issue.
+
+## Hacking
+
+To get started you'll need the latest GHC release installed.
+
+Clone the repository:
+
+```bash
+git clone https://github.com/haskell/haddock.git
+cd haddock
+```
+
+### Git Branches
+
+Please **always** base your pull request on the current GHC version branch
+(`ghc-9.0` for instance). The PR will be forward-ported to `ghc-head`
+so that GHC can use it.
+
+### Building the packages
+
+#### Using `cabal`
+
+Requires cabal `>= 3.4` and GHC `== 9.0`:
+
+```bash
+cabal v2-build all --enable-tests
+cabal v2-test all
+```
+
+#### Using `stack`
+
+```bash
+stack init
+stack build
+export HADDOCK_PATH="$(stack exec which haddock)"
+stack test
+```
+
+### Updating golden testsuite outputs
+
+If you've changed Haddock's output, you will probably need to accept the new
+output of Haddock's golden test suites (`html-test`, `latex-test`,
+`hoogle-test`, and `hypsrc-test`). This can be done by passing the `--accept`
+argument to these test suites. With a new enough version of `cabal-install`:
+
+```
+cabal v2-test html-test latex-test hoogle-test hypsrc-test \
+  --test-option='--accept'
+```
+
+
+[SSCCE]: http://sscce.org/
+