这可能是this post的副本 . 但它得到的唯一答案对我来说似乎不起作用,所以我在这里发布自己的案例,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) .
我用uskell的方式写了这个C库的haskell绑定 . Main.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来测试这个程序,将它传递给它和它可以找到它的目录: ghci /usr/local/lib/ -lMyLib
它运行得很好 .
现在,独立地,我正在尝试开始使用堆栈,并且在this guide之后,我能够构建几个非平凡的程序示例 .
但是,我无法堆叠构建上面的FFI Main.hs程序,因为它抱怨丢失的C库:
First try :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:
- 将
extra-lib-dirs: [/usr/local/lib]
添加到stack.yaml文件中 . - 将
extra-include-dirs: [/usr/local/lib]
添加到stack.yaml文件中(虽然可能不需要) . - 在标签可执行文件或库下的项目cabal文件中添加了
extra-libraries: lMyLib
(我也尝试了extra-libraries: libMyLib.so
,结果相同) .
Second try :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)
是否与此相关 .
My Question : 我被困在这里 . 我还应该对yaml或cabal文件或其他地方做任何其他事情,以便 stack build
找到C库吗?
1 回答
extra-libraries
应该只有基本库名称,因此请使用extra-libraries: MyLib
.