问题
Here's the error I see when trying to load a .hs file into ghci.
>Loading package http-enumerator-0.7.1.1 ... linking ... done.
>Loading package double-conversion-0.2.0.1 ... can't load .so/.DLL for: stdc++ ?>>> (libstdc++.so: cannot open shared object file: No such file or directory)
Further investigation reveals I have multiple stdc++ libraries installed
>locate libstdc++.so
>/usr/lib/libstdc++.so.6
>/usr/lib/libstdc++.so.6.0.14
>/usr/lib/gcc/x86_64-linux-gnu/4.4/libstdc++.so
>/usr/lib32/libstdc++.so.6
>/usr/lib32/libstdc++.so.6.0.14
I thought maybe I could make a symlink to what it wants, but I have no idea which one. I'm using this OS 2.6.35-22-server #33-Ubuntu SMP Sun Sep 19 20:48:58 UTC 2010 x86_64 GNU/Linux
How can I tell exactly what it wants?
回答1:
The ones in /usr/lib symlink to one file:
$ ls -l libstdc++*
lrwxrwxrwx 1 root root 19 2011-09-24 22:14 libstdc++.so.6 -> libstdc++.so.6.0.13
-rw-r--r-- 1 root root 1044112 2010-03-26 20:16 libstdc++.so.6.0.13
Just run:
sudo ln -si /usr/lib/libstdc++.so.6 /usr/lib/libstdc++.so
and it should work.
回答2:
/usr/lib/libstdc++.so.6 should be a symlink to /usr/lib/libstdc++.so.6.0.14. This is probably the version you need.
/usr/lib32/libstdc++.so.6 should be a symlink to /usr/lib32/libstdc++.so.6.0.14, they are for 32-bit programs, you don't normally need them.
/usr/lib/gcc/x86_64-linux-gnu/4.4/libstdc++.so is the problem.
double-conversion-0.2.0.1 probably has got linked against it, and ghci cannot find it. Normally everything should be linked against libstdc++.so.6, not libstdc++.so without a version suffix.
I think one should not have a version-less libstdc++.so at all anywhere in the system. (There's none on my gentoo box for example.) It is dangerous, as different major versions of libstdc++ are usually binary incompatible. Try removing the library you have under /usr/lib/gcc/, then reinstall gcc and see if it gets installed again.
If it does get installed, then a symlink named /usr/lib/libstdc++.so pointing to /usr/lib/libstdc++.so.6 should solve this problem. I'm not sure this would be the right way to solve it in the long run though.
These are things I have found through experiments with my own Linux box. I am not an expert in Ubuntu, it may do things differently from other Linuxes.
回答3:
To work around the issue on 64-bit Fedora 16:
sudo ln -si /usr/lib64/libstdc++.so.6 /usr/lib64/libstdc++.so
来源：https://stackoverflow.com/questions/7761880/how-can-i-tell-which-libstdc-double-conversion-wants