<div class="hidden-warning"><a href="https://docs.haskellstack.org/"><img src="https://cdn.jsdelivr.net/gh/commercialhaskell/stack/doc/img/hidden-warning.svg"></a></div>

# Adding a new GHC version

* Push new tag to our fork. Command:

    ~~~text
    git clone git@github.com:commercialhaskell/ghc.git
    cd ghc
    git remote add upstream https://gitlab.haskell.org/ghc/ghc.git
    git fetch upstream
    git push origin ghc-X.Y.Z-release
    ~~~

* [Publish a new GitHub release](https://github.com/commercialhaskell/ghc/releases/new)
  with tag `ghc-X.Y.Z-release` and same name, with description noting where the
  binidsts are mirrored from. For example:

    ~~~text
    Unless otherwise indicated, bindists are mirrored from https://downloads.haskell.org/~ghc/
    * FreeBSD bindists are mirrored from http://distcache.FreeBSD.org/local-distfiles/arrowd/stack-bindists
    * musl bindists are mirrored from https://github.com/redneb/ghc-alt-libc/releases
    ~~~

* Download all the relevant GHC bindists from their sources, and upload them to
  the just-created GitHub release (see
  [stack-setup-2.yaml](https://github.com/fpco/stackage-content/blob/master/stack/stack-setup-2.yaml)
  for the ones we used in the last GHC release).

  In the case of macOS, repackage the `.xz` bindist as a `.bz2`, since macOS
  does not include `xz` by default or provide an easy way to install it.

  The script at `etc/scripts/mirror-ghc-bindists-to-github.sh` will help with
  this. See the comments within the script.

* [Edit stack-setup-2.yaml](https://github.com/fpco/stackage-content/edit/master/stack/stack-setup-2.yaml)
  and add the new bindists, pointing to the GitHub release version. Be sure to
  update the `content-length` and `sha1` values.

  Before committing, test using a command like:

    ~~~text
    stack --snapshot=ghc-X.Y.Z setup --setup-info-yaml=path/to/stackage-content/stack/stack-setup-2.yaml
    ~~~

* In [stackage-content](https://github.com/fpco/stackage-content), command:

    ~~~text
    cd stack
    ./update-global-hints.hs ghc-X.Y.Z
    ~~~

  and commit the changes.

## Building GHC

**NOTE: We are no longer building custom GHC bindists.  This section remains for future reference, but GHC's build system has changed substantially since it was written.**

TODO: look into using
https://github.com/bgamari/ghc-utils/blob/master/rel-eng/bin-release.sh, which
is the script used to official bindists.

On systems with a small `/tmp`, you should set TMP and TEMP to an alternate
location.

Setup the system based on these
[instructions](https://gitlab.haskell.org/ghc/ghc/wikis/building/preparation/linux).
On Ubuntu (`docker run -ti --rm ubuntu:16.04`):

~~~text
apt-get update
apt-get install -y ghc alex happy make autoconf g++ git vim xz-utils automake libtool gcc libgmp-dev ncurses-dev libtinfo-dev python3
~~~

On Void Linux (`docker run -ti --rm voidlinux/voidlinux bash`) command:

~~~text
xbps-install -S curl gcc make xz ghc autoconf git vim automake gmp-devel ncurses-devel python3 cabal-install
cabal update
cabal install alex happy
~~~

For GHC >= 7.10.2, set the `GHC_VERSION` environment variable to the version to
build:

* `export GHC_VERSION=8.2.2`
* `export GHC_VERSION=8.2.1`
* `export GHC_VERSION=8.0.2`
* `export GHC_VERSION=8.0.1`
* `export GHC_VERSION=7.10.3a`
* `export GHC_VERSION=7.10.2`

then, from
[here](https://gitlab.haskell.org/ghc/ghc/wikis/building/quick-start), command:

~~~text
git config --global url."git://github.com/ghc/packages-".insteadOf git://github.com/ghc/packages/
git clone -b ghc-${GHC_VERSION}-release --recursive https://gitlab.haskell.org/ghc/ghc.git ghc-${GHC_VERSION}
cd ghc-${GHC_VERSION}/
cp mk/build.mk.sample mk/build.mk
sed -i 's/^#BuildFlavour *= *perf$/BuildFlavour = perf/' mk/build.mk
./boot
./configure --enable-tarballs-autodownload
sed -i 's/^TAR_COMP *= *bzip2$/TAR_COMP = xz/' mk/config.mk
make -j$(cat /proc/cpuinfo|grep processor|wc -l)
make binary-dist
~~~

GHC 7.8.4 is slightly different. Command:

~~~text
export GHC_VERSION=7.8.4
git config --global url."git://github.com/ghc/packages-".insteadOf git://github.com/ghc/packages/
git clone -b ghc-${GHC_VERSION}-release --recursive https://gitlab.haskell.org/ghc/ghc.git ghc-${GHC_VERSION}
cd ghc-${GHC_VERSION}/
./sync-all --extra --nofib -r git://git.haskell.org get -b ghc-7.8
cp mk/build.mk.sample mk/build.mk
sed -i 's/^#BuildFlavour *= *perf$/BuildFlavour = perf/' mk/build.mk
perl boot
./configure
sed -i 's/^TAR_COMP *= *bzip2$/TAR_COMP = xz/' mk/config.mk
make -j$(cat /proc/cpuinfo|grep processor|wc -l)
make binary-dist
~~~