交叉编译haskell代码时如何安装依赖项? [英] How do I install dependencies when cross compiling haskell code?

问题描述

我已经成功创建了一个 ghc 交叉编译器，它允许我从我的 x64 linux 机器为 armv6h(在我的例子中是树莓派)编译 haskell 代码.我已经在树莓派上成功运行了 hello world 程序.

I've successfully created a ghc cross compiler, that allows me to compile haskell code for armv6h (raspberry pi in my case) from my x64 linux machine. I've successfully run a hello world program on the raspberry.

不，我想构建我的真实应用程序，它对其他 haskell 模块有很多依赖.当我为 x64 编译时，我只是这样做

No I want to build my real app, which has a lot of dependencies on other haskell modules. When I compile for x64 I simply do

cabal install dependenciy1 depenency2 ...

我知道我可以让我自己的程序成为一个阴谋项目，并自动执行这一步.但这不是重点.

I know I could make my own programm a cabal-project an automate this step. But that's not the point here.

当我尝试使用交叉编译器时

When I try to use the cross-compiler

arm-unknown-linux-gnueabi-ghc --make myapp.hs

它告诉我它找不到的模块.当然，它们没有安装！

It tells me about modules it could not find. Of course, they are not installed!

我阅读了https://ghc.haskell.org/trac/ghc/wiki/建筑/交叉编译并据此我试过

cabal --with-ghc=arm-unknown-linux-gnueabi-ghc --with-ghc-pkg=arm-unknown-linux-gnueabi-ghc-pkg --with-ld=arm-unknown-linux-gnueabi-ld install random

random 是我要在这里安装的依赖项.我收到以下错误:

random is the depenency I'm trying to install here. I get the following error:

Resolving dependencies...
Configuring random-1.0.1.3...
Failed to install random-1.0.1.3
Last 10 lines of the build log ( /home/daniel/.cabal/logs/random-1.0.1.3.log ):
/home/daniel/.cabal/setup-exe-cache/setup-Cabal-1.18.1.3-arm-linux-ghc-7.8.3.20140804: /home/daniel/.cabal/setup-exe-cache/setup-Cabal-1.18.1.3-arm-linux-ghc-7.8.3.20140804:      cannot execute binary file
cabal: Error: some packages failed to install:
random-1.0.1.3 failed during the configure step. The exception was:
ExitFailure 126

当我这样做

file /home/daniel/.cabal/setup-exe-cache/setup-Cabal-1.18.1.3-arm-linux-ghc-7.8.3.20140804

我明白了

/home/daniel/.cabal/setup-exe-cache/setup-Cabal-1.18.1.3-arm-linux-ghc-7.8.3.20140804: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 3.10.2, not stripped

难怪它不能执行它.它是为 arm 编译的.

No wonder it can't execute it. It's compiled for arm.

我在这里遗漏了什么吗?我的目标是引入所有依赖项，然后创建一个可以在我的树莓派上部署的静态链接应用.

Am I missing something here? My goal is to pull in all dependencies, then create a statically linked app that I can deploy on my raspberry.

推荐答案

要了解此错误，您需要了解 cabal install 内部是如何工作的.本质上，它将执行以下步骤:

To understand this error, you need to know how cabal install works internally. In essence, it will perform the following steps:

1. 下载并解压源代码
2. 编译Setup.hs(此文件用于构建系统的自定义，例如，您可以在configure阶段实现一些钩子来运行额外的haskell代码).
3. 运行 setup configure &&设置构建&&设置安装

1. Download and unpack the source code
2. Compile Setup.hs (this file is used for customization of the build system, for example, you can implement some hooks to run additional haskell code in the configure phase).
3. Run setup configure <configure flags> && setup build && setup install

现在的问题是 cabal install 也将 --with-ghc 给定的 GHC 用于第 2 步，但该步骤生成的可执行文件必须在主机系统！

The problem is now that cabal install uses the GHC given by --with-ghc also for step 2, but the executable produced by that step must run on the host system!

一种解决方法是手动执行这些步骤，这意味着您可以完全控制.首先获取源码:

A workaround is to do the steps manually, which means you have full control. First, get the source:

$ cabal get random
Downloading random-1.0.1.3...
Unpacking to random-1.0.1.3/
$ cd random-1.0.1.3

然后，使用 host ghc 编译 Setup.hs:

Then, compile Setup.hs, using the host ghc:

$ ghc ./Setup.hs -o setup

最后，配置、构建和安装.正如@Yuras 在评论中所建议的，我们还添加了用于运行 hsc2hs 的 -x 选项:

And finally, configure, build and install. As suggested by @Yuras in a comment, we also add the -x option for running hsc2hs:

$ ./setup configure ----with-ghc=arm-unknown-linux-gnueabi-ghc --with-ghc-pkg=arm-unknown-linux-gnueabi-ghc-pkg --with-ld=arm-unknown-linux-gnueabi-ld --hsc2hs-options=-x
$ ./setup build && ./setup install

关于这个已经有一个阴谋集团的问题:https://github.com/haskell/cabal/issues/2085

There is already a cabal issue about this: https://github.com/haskell/cabal/issues/2085

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