Support musl-based Linux distributions like Alpine Linux

borsboom commented 8 years ago

@dysinger has had success building Stack on Alpine using GHC 8.0.1 from here: https://github.com/mitchty/alpine-linux-ghc-bootstrap. Once there is a Stackage LTS release that uses GHC 8, we can consider adding official support for Alpine Linux.

nh2 commented 6 years ago

I have also now uploaded a prerelease static musl build for stack-1.9.0.1 on https://github.com/nh2/stack/releases/tag/v1.6.5 and would appreciate testing.

hasufell commented 6 years ago

As far as I remember, system-ghc picks it from PATH, so you could do PATH=/path/to/desired/ghc/bin:$PATH stack build

I don't understand what that means. I'm talking about the alpine ghc packages, see https://pkgs.alpinelinux.org/packages?name=ghc&branch=edge

Also, I think you can use stack's feature to configure custom compilers, so these might be two workarounds for now.

There is no custom compiler to install that works under alpine. GHC upstream doesn't provide one, stack doesn't and the distro only provides one arbitrary version, as already explained.

nh2 commented 6 years ago

@hasufell I know that there's currently no ghc available on Alpine, I was just referring to

system-ghc you can have, not multiple at the same time

which sounded like "if there were multiple compilers available, it would be difficult to switch them using system-ghc". But perhaps I misunderstood what you meant to say with that, and you meant something else?

hasufell commented 6 years ago

I wasn't talking about the command system-ghc.

rhizoome commented 6 years ago

@nh2 Of course there is ghc on Alpine: https://pkgs.alpinelinux.org/packages?name=ghc&branch=v3.8

I use it every day, but since stack cannot bootstrap on Alpine you have to use "system-ghc", which is the ghc version above. That's not like stack is meant to be used, so at the moment I rather use: cabal new-*

ketzacoatl commented 5 years ago

@mitchty (or anyone else watching this thread), I'd like to build bindists for alpine, where do I get started?

borsboom commented 5 years ago

It looks like @redneb is building musl-based GHC bindists for recent GHC releases, and people seem to be able to install them on Alpine Linux using the standard ./configure --prefix=… && make install that stack setup uses. In theory, this may be all Stack needs to fully support Alpine Linux (plus a bit of logic to detect when running on a musl-based distro and choose a different bindist to download).

Any interested Alpine user out there who can give this a try? You'd use the setup-info configuration to point stack setup to the right bindist.

edit: I see I linked to these a couple of years ago, but it doesn't look like anybody actually tried them (perhaps due to the following comment).

borsboom commented 5 years ago

Update: I decided to try this myself. I added the following to my ~/.stack/config.yaml:

setup-info:                                                                                                                                    
  ghc:                                                                                                                                         
    linux64-ncurses6:                                                                                                                          
      8.6.5:                                                                                                                                   
        url: "https://github.com/redneb/ghc-alt-libc/releases/download/ghc-8.6.5-musl/ghc-8.6.5-x86_64-unknown-linux-musl.tar.xz"

And then ran stack setup, which worked (once I apk added the right prerequisites). I've been able to build a "hello world" program both as a dynamically linked and as a statically linked binary (using stack build --ghc-options='-optl-static -optl-pthread'), and it seems to work. Next up: trying out building stack itself statically linked.

borsboom commented 5 years ago

Note for whomever implements detection of musl-based distributions: this node package appears to have decent libc detection logic that we could use as inspiration: https://github.com/lovell/detect-libc/blob/master/lib/detect-libc.js

borsboom commented 5 years ago

Next up: trying out building stack itself statically linked.

This seems to have worked as well.

However, there is a problem that's exposed when I try to use the bindist with the upcoming stack-2.1 which does some extra sanity checking (I had been using stack-1.9.3 before): it fails to install a haddock binary.

Downloaded ghc-ncurses6-8.6.5.               
[…]
Installed GHC.
Found an invalid compiler at "/root/.stack/programs/x86_64-linux/ghc-ncurses6-8.6.5/bin/ghc-8.6.5": Control.Exception.Safe.throwString called with:

Could not find any of: ["/root/.stack/programs/x86_64-linux/ghc-ncurses6-8.6.5/bin/haddock-8.6.5","/root/.stack/programs/x86_64-linux/ghc-ncurses6-8.6.5/bin/haddock-ghc-8.6.5","/root/.stack/programs/x86_64-linux/ghc-ncurses6-8.6.5/bin/haddock","/root/.stack/programs/x86_64-linux/ghc-ncurses6-8.6.5/bin/haddock-ghc"]

Opened an issue on ghc-alt-libc for this here: https://github.com/redneb/ghc-alt-libc/issues/5

borsboom commented 5 years ago

@redneb has very kindly, and quickly, uploaded new ghc 8.6.5 bindists that fix the haddock issue. I've tested them with stack-2.1 and they seem to work great (including stack haddock). I've gone ahead and added stack setup metadata for them in https://github.com/commercialhaskell/stackage-content/commit/f6eb573456c13457d75cb5cc8b3ddfe878147c90 with a new -musl OS key suffix.

Now what's left is adding logic to stack setup to detect when running on a musl-based distro and use the new -musl OS key suffix to choose the bindist.

redneb commented 5 years ago

I have two remarks about this:

It would be better to install ghc using ./configure --disable-ld-override --prefix=… && make install. Without the --disable-ld-override option, ghc will try to use ld.gold as its linker, which in my tests causes it to segfault. This might not be needed for alpine because its binutils package does not install ld.gold, but it might cause problems in other musl based environments such as gentoo musl (which includes ld.gold by default).
I produce my ghc binaries in a gentoo musl system. This could potentially cause issues in the future, if the sonames for libgmp and libncursesw do not match between gentoo and alpine. Of course this is a more general problem, even with glibc based builds.

nh2 commented 5 years ago

ghc will try to use ld.gold as its linker, which in my tests causes it to segfault

@redneb Is that filed somewhere? GHC should not segfault when using gold.

redneb commented 5 years ago

@redneb Is that filed somewhere? GHC should not segfault when using gold.

No I have not filed any bug for that, but I am not sure if this an issue with ghc. I am not sure if ld.gold is officially supposed to work under musl; in the past I even had issues with the gcc + ld.gold combination under musl, although admittedly, not any anymore.

nh2 commented 5 years ago

@redneb I remember hearing/reading about some musl+gold problems, but I am quite sure that their respective authors want that these work well together.

So even if there's a segfault in gold itself, it would be very useful to post it somewhere.

Is it perhaps https://sourceware.org/bugzilla/show_bug.cgi?id=23856 (which I filed from https://github.com/NixOS/nixpkgs/issues/49071#issuecomment-435663380)?

redneb commented 5 years ago

Is it perhaps https://sourceware.org/bugzilla/show_bug.cgi?id=23856 (which I filed from NixOS/nixpkgs#49071 (comment))?

This sounds awfully a lot like the issue I was seeing: the binaries I get from ghc+ld.gold segfault immediately when I run them. I created redneb/ghc-alt-libc#6 to track this issue.

(apologies to everyone for the off topic spam)

borsboom commented 5 years ago

(apologies to everyone for the off topic spam)

I'm actually tempted to rename this issue to "Support musl-based Linux distributions" rather than Alpine Linux specifically, so it's not off topic in that case :)

Until GHC release team is releasing battle-tested musl-based bindists officially, I don't think we can "officially" support Alpine Linux anyway in Stack, so I'm not sure that part of the issue title should be a hold up either. But decent experimental support for musl-based distributions would be a huge step forward (in particular, being able to use it with an Alpine-based docker image that works with --docker would make building statically linked Linux binaries really easy).

Anyone have any objections to me renaming the issue to "Support musl-based Linux distributions like Alpine Linux"?

nh2 commented 4 years ago

Anyone have any objections to me renaming the issue to "Support musl-based Linux distributions like Alpine Linux"?

@borsboom Doesn't seem so, let's do it.

dellelce commented 4 years ago

Hi, just wanted to confirm that this is still current exactly 4 years after ticket was initially opened.

I am having the same issue attempting to use "stack" for building "postgrest" on alpine 3.12 with currently available ghc on alpine.

hasufell commented 4 years ago

alpine musl GHCs are already part of the official bindists: https://downloads.haskell.org/~ghc/8.10.1/

mpilgrem commented 6 months ago

I am closing this issue given the passage of time and because Stack 2.15.3 does support Alpine Linux/x86_64 (tested via WSL).

commercialhaskell / stack

Support musl-based Linux distributions like Alpine Linux #2387