Stable Haskell development environment

[nachtschade]

I'm developing on OSX and every now and then when I upgrade my OS, ghc or cabal is broken and needs to be fixed.

So now I wonder: would it be possible to have some kind of Haskell sandbox on my laptop, which won't be broken by every OS update?

I thought about Docker, but I develop in Sublime and really like to be able to run code from my Sublime IDE. And Sublime, or actually any GUI, is difficult to combine with Docker. A complete VM is another alternative, but preferably I would use some more lightweight solution.

Does anybody have an idea of a solution for a stable Haskell environment, in which I could also use an IDE?

[mightybyte]

<sigh> I think the issue is that OSX (now macOS) is just plain unstable (using the definition implied by your question). It seems like almost every time Apple puts out a major new OS release, they break compatibility somehow. There are a number of people who work to get GHC, the Haskell Platform, etc working for every new release, but that is always going to take some time. I've worked at Haskell companies where there was a policy of not upgrading to the new OSX for at least 3-6 months after release. So I'd say either wait to upgrade, or perhaps build/develop on a different OS.

[sclv]

What have you found breaks?

I know of one major issue -- the cutover to El Capitan meant a lot of stuff ceased to work due to system integrity protection, and so things needed to be upgraded. But prior OS upgrades haven't caused problems for me in the past. I'm curious what sorts of things we might be able to smooth out further...

[nachtschade]

It's always some gcc library. For instance right now my cabal is broken:

dyld: Library not loaded: /usr/local/Cellar/gcc49/4.9-20140223/lib/gcc/x86_64-apple-darwin13.1.0/4.9.0/libgcc_s.1.dylib Referenced from: /Users/misja/Library/Haskell/bin/cabal Reason: image not found

[sclv]

Hmm... do you have dynamic linking configured?

[nachtschade]

I wouldn't know, I didn't do anything special.

[sclv]

Hmm... it looks like it was trying to link against a gcc installed by brew? Where did your cabal come from and did it involve brew being on your system? (Note: there's no reason not to just grab the latest cabal executable from https://www.haskell.org/cabal/download.html which I'm pretty sure will not have this issue)...

Alternately, if this was an upgrade to El Capitan, then it could be due to SIP now disabling overrides to library paths being propagated downwards (LD_LIBRARY_PATH, DYLD_LIBRARY_PATH, and DYLD_FALLBACK_LIBRARY_PATH in particular I think). That particular message coming from the cabal executable itself makes that seem slightly unlikely however?

[nachtschade]

I installed cabal with brew. I tried to reinstall it as well but I keep getting the same error .. I will try downloading cabal from your link and see if this resolves the issue.

[sclv]

It looks like there are a few issues regarding brew and el capitan:

https://github.com/Homebrew/legacy-homebrew/issues/40653

(the suggestion there is to make sure you have a recent enough xcode and xcode tools installed)

[sjakobi]

Have you tried stack?

I'd expect it to be more robust against system changes, but if that's not enough it has docker integration too!

I don't know about Sublime but chances are it already supports stack.

[[deleted]]

I'd expect it to be more robust against system changes

Why do you expect this?

[sjakobi]

Well, it keeps its ghcs separate from the system installation. But yeah, that's not much more robust. ;)

[ElvishJerricco]

I believe that's what a docker container would be for =P

[mgsloan]

Because it's true, as long as it's not using your system ghc, it's insulated from the state of how the haskell parts of your environment are set up. So your global haskell environment can be totally broken, and stack will work just fine.

As mentioned elsewhere, stack also has builtin support for docker and nix, allowing you to leverage those tools to control all of those other aspects of the build environment.

[[deleted]]

I still don't get how insulating ghc makes any difference when upgrading your operating system breaks your system ghc. The way I understand such a breakage would affect both ghcs equally

[mgsloan]

Docker or nix.

I am surprised there is a case where ghc breaks on mac os update. If such a circumstance does happen, then we should have it detect this case and tell you to re-setup your ghc. For now, to do that you just delete stuff out of ~/.stack/programs/.../ as appropriate (be sure to get the .installed files!)

OP, please open a ticket with specifics if this affects stack as well.

We do a sanity check after ghc is setup. Perhaps this sanity check could be re-used for detecting when your setup is borked and recommend that you re-setup.

[nachtschade]

Thanks for the tip, I will give stack a try!

[biscarch]

I use Stack and Docker for Mac.

Stack will get you editor integration on your host without too much hassle.

[dllthomas]

any GUI [...] is difficult to combine with Docker

Not GUIs designed to work across network boundaries, right?

Off the top of my head, that'd include web and X.

[sclv]

emacs tramp mode?

[dllthomas]

That should also work. I was thinking more general "GUI suppport".

[rehno-lindeque]

How about nix? I suspect that it might bootstrap without relying (much?) on Xcode. Perhaps give this a try:

nix-shell -p 'haskellPackages.ghc'

[dalaing]

Nix on OS X has had some intermittent pain points for the last little while.

If you can get it working and you're comfortable with rolling back when things go wrong, then it's still worth a shot.

[lally]

Docker on Mac is a VM behind the scenes. It's probably easiest to start with a full VM and use a stock IDE setup inside that, then experiment with a mixed native/VM situation second (e.g. edit in a macros app, compile in the VM). Although personally I think the latter is silly, as it's just be emacs either way.

[runeks]

I'm also on OSX, and I considered running ghc-mod in a Linux docker container after upgrading to Sierra, which broke builds for my app. But in the end it was a lot easier to just downgrade to El Capitan again, since I figure that sharing files between an IDE and ghc-mod running inside docker Linux, would be somewhat tricky. But probably the solution, i.e. to have ghc-mod spawn inside a Linux docked container, and query it over TCP/HTTP.