A simple haskell project to investigate static linking on linux using Nix.

THIS IS STILL A WORK IN PROGRESS

IMHO, the main reason to statically link an haskell executable is to be able to deploy without to much headache in environment managed by a third party. In my case such environment is AWS Lambda.

I've had some success building static executables using Alpine Linux in a docker container, however trying to move from ghc-8.0.2 to ghc-8.2.2 has been impossible since 8.2.2 is not available, as of 2017-12-13, in Alpine Linux and fpcomplete does not provide a suitable binary distribution.

In order to link an executable statically you must add the -fPIC flag to ghc in stack.yaml:

ghc-options:
	'$locals': '-fPIC'
	'$everything': '-fPIC'

If you are using stack version 1.5.1 or previous replace the following fragment with:

ghc-options:
	'*': '-fPIC'

In yout .cabal file:

executable your-executable
  ld-options:	-static

You must add the -pthread flag to ghc, so the previous stack.yaml fragment becomes:

ghc-options:
	'$locals': '-fPIC -optl-pthread'
	'$everything': '-fPIC'

As of version 1.6.1 you need to add a shell.nix file to your project.

You can find an exemple included in this simple project. The important points are:

1. by default ghc produces executables that are dynamically linked with libgmp. To avoid this behaviour a ghc variant with support for integer-simple must be used.

2. the shared variant of glibc is required at compile time, since one of the program used by stack is dinamically linked.

3. the static variant of glibc is required to produce a statically linked executable.