这可能是这篇文章的副本。但它得到的唯一答案似乎对我不起作用,所以我在这里发布我自己的案例,希望找到一个具体的解决方案。我在 Linux Ubuntu Trusty 上。
我有一个专有的 C 库 libMyLib.so,位于 /usr/local/lib(包含在 LD_LIBRARY_PATH 中)。
我以通常的方式将 haskell 绑定写到了这个 C 库。主要.hs:
{-# LANGUAGE ForeignFunctionInterface #-}
module Main where
import Foreign
import Foreign.C.Types
foreign import ccall safe "mycfunction" c_myCfunction :: CInt -> IO (CInt)
-- etc...
main = do -- ...
我可以用 ghci 测试这个程序,将库和可以找到它的目录传递给它:ghci /usr/local/lib/ -lMyLib
它工作得很好。
现在,独立地,我正在尝试开始使用堆栈,并且按照本指南,我能够构建几个非平凡的程序示例。
但是,我无法堆栈构建上面的 FFI Main.hs 程序,因为它抱怨缺少 C 库:
第一次尝试 :
me@user:~/myProject$ stack build
myProject-0.1.0.0: configure
Configuring myProject-0.1.0.0...
myProject-0.1.0.0: build
Preprocessing library myProject-0.1.0.0...
In-place registering myProject-0.1.0.0...
Preprocessing executable 'myProject-exe' for myProject-0.1.0.0...
Linking .stack-work/dist/x86_64-linux/Cabal-1.22.5.0/build/myProject-exe/myProject-exe ...
.stack-work/dist/x86_64-linux/Cabal-1.22.5.0/build/myProject-exe/myProject-exe-tmp/MyModule.o: In function `c8QI_info':
(.text+0x102b): undefined reference to `MyModule_mycfunction'
collect2: error: ld returned 1 exit status
-- While building package myProject-0.1.0.0 using:
/home/me/.stack/setup-exe-cache/x86_64-linux/setup-Simple-Cabal-1.22.5.0-ghc-7.10.3 --builddir=.stack-work/dist/x86_64-linux/Cabal-1.22.5.0 build lib:myProject exe:myProject-exe --ghc-options " -ddump-hi -ddump-to-file"
Process exited with code: ExitFailure 1
在第二次尝试之前,我确实添加了以下内容:
- 添加extra-lib-dirs: [/usr/local/lib]
到 stack.yaml 文件中。
- 添加extra-include-dirs: [/usr/local/lib]
到 stack.yaml 文件中(尽管可能不需要)。
-extra-libraries: lMyLib
在项目的 cabal 文件中添加到可执行文件或库标签下(我也尝试extra-libraries: libMyLib.so
过相同的结果)。
第二次尝试:
me@user:~/myProject$ stack build
myProject-0.1.0.0: configure
Configuring myProject-0.1.0.0...
setup-Simple-Cabal-1.22.5.0-ghc-7.10.3: Missing dependency on a foreign
library:
* Missing C library: lMyLib
This problem can usually be solved by installing the system package that
provides this library (you may need the "-dev" version). If the library is
already installed but in a non-standard location then you can use the flags
--extra-include-dirs= and --extra-lib-dirs= to specify where it is.
-- While building package myProject-0.1.0.0 using:
/home/me/.stack/setup-exe-cache/x86_64-linux/setup-Simple-Cabal-1.22.5.0-ghc-7.10.3 --builddir=.stack-work/dist/x86_64-linux/Cabal-1.22.5.0 configure --with-ghc=/home/me/.stack/programs/x86_64-linux/ghc-7.10.3/bin/ghc --with-ghc-pkg=/home/me/.stack/programs/x86_64-linux/ghc-7.10.3/bin/ghc-pkg --user --package-db=clear --package-db=global --package-db=/home/me/.stack/snapshots/x86_64-linux/lts-4.0/7.10.3/pkgdb --package-db=/home/me/myProject/.stack-work/install/x86_64-linux/lts-4.0/7.10.3/pkgdb --libdir=/home/me/myProject/.stack-work/install/x86_64-linux/lts-4.0/7.10.3/lib --bindir=/home/me/myProject/.stack-work/install/x86_64-linux/lts-4.0/7.10.3/bin --datadir=/home/me/myProject/.stack-work/install/x86_64-linux/lts-4.0/7.10.3/share --libexecdir=/home/me/myProject/.stack-work/install/x86_64-linux/lts-4.0/7.10.3/libexec --sysconfdir=/home/me/myProject/.stack-work/install/x86_64-linux/lts-4.0/7.10.3/etc --docdir=/home/me/myProject/.stack-work/install/x86_64-linux/lts-4.0/7.10.3/doc/myProject-0.1.0.0 --htmldir=/home/me/myProject/.stack-work/install/x86_64-linux/lts-4.0/7.10.3/doc/myProject-0.1.0.0 --haddockdir=/home/me/myProject/.stack-work/install/x86_64-linux/lts-4.0/7.10.3/doc/myProject-0.1.0.0 --dependency=base=base-4.8.2.0-0d6d1084fbc041e1cded9228e80e264d --dependency=bytestring=bytestring-0.10.6.0-9a873bcf33d6ce2fd2698ce69e2c1c66 --dependency=safe=safe-0.3.9-e3aa437cf6afe091d2ac3ab91bc10ddd --dependency=split=split-0.2.2-10f39ee49f650eefddf38af51b65d10a --extra-include-dirs=/usr/local/lib --extra-lib-dirs=/usr/local/lib --enable-tests --enable-benchmarks
Process exited with code: ExitFailure 1
所以现在它知道它需要哪个 C 库,因为它抱怨它,同时添加了正确的额外库目录(参见错误消息的最后)。我不确定评论(you may need the "-dev" version)
是否相关。
我的问题:我被困在这里。我还应该对 yaml 或 cabal 文件或其他地方做些什么,以便stack build
找到 C 库?