Editing OpenWRT (section)

== Native GHC for musl ==

Given the issues with cabal and Template Haskell when cross-compiling, the best solution (for x86_64, at least) may be a native GHC compiler which is linked against musl.

[https://mail.haskell.org/pipermail/haskell-cafe/2015-May/119843.html Marios Titas has a haskell-cafe post] and a [https://github.com/redneb/ghc-alt-libc/ github repository] about a musl-native ghc toolchain.

If you prefer Docker over chroot, there is [https://hub.docker.com/r/nilcons/ghc-musl/ a Docker image] based on [https://alpinelinux.org/about/ Alpine Linux], and the corresponding Dockerfile is [https://github.com/nilcons/ghc-musl on github].

Here is an example of using that Docker image to build a static executable with cabal:

<pre>
ppelletier@patrick64:~$ sudo docker run -it nilcons/ghc-musl:cabal sh
Unable to find image 'nilcons/ghc-musl:cabal' locally
cabal: Pulling from nilcons/ghc-musl
c862d82a67a2: Pull complete
00b183080618: Pull complete
7193868286e6: Pull complete
a3ed95caeb02: Pull complete
bbfc077cc684: Pull complete
Digest: sha256:27657bba49ed54b57d10c964ff59fc275d47d26e3e3a8e5991c61edc9f5f40b2
Status: Downloaded newer image for nilcons/ghc-musl:cabal
/ # cabal update
Downloading the latest package list from hackage.haskell.org
/ # cabal install --ghc-option=-optl-static hello
Resolving dependencies...
Configuring hello-1.0.0.2...
Building hello-1.0.0.2...
Installed hello-1.0.0.2
/ # which hello
/root/.cabal/bin/hello
/ # hello
Hello, World!
/ # file /root/.cabal/bin/hello
/root/.cabal/bin/hello: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, stripped
/ # ldd /root/.cabal/bin/hello
ldd: /root/.cabal/bin/hello: Not a valid dynamic program
</pre>

[[Category:OS]]