GLIBCXX_3.4.9 not found

Question

Hi,

I have a problem concerning libstdc++.so.

I installed a new version of gcc and tried to compile c++ code. The compiling worked, but when I try to execute the binary (m5.opt is its name) I've got the following error: build/ALPHA_SE/m5.opt: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.9' not found (required by build/ALPHA_SE/m5.opt).

Do I need to replace libstdc++.so? And if so, where can I download the version I want? On the GCC-website they say libstdc++ is a part of gcc now.

I hope somebody can help me out! I'm only 4 months on Linux now, so everything is very new for me.

Max

details

GCC:
I had gcc 4.1.2 before, but I downloaded gcc 4.2.4. From the untarred gcc-directory I executed "./configure"; "make"; "sudo make install". When I tried to use gcc or g++ to compile, it's default version was still 4.1.2. To overcome this I replaced some links:
mv /usr/bin/gcc /usr/bin/gcc_bak
ln -s /usr/local/bin/gcc gcc
mv /usr/bin/g++ /usr/bin/g++_bak
ln -s /usr/local/bin/g++ g++

GLIBC(++) -- libstdc++:
/usr/lib64/libstdc++.so.6 -> libstdc++.so.6.0.8
/usr/local/lib/libstdc++.so -> libstdc++.so.6.0.9
/lib/libc.so.6 -> libc-2.5.so -> libc-2.5.so

Linux-version:
uname -a gives: Linux madmax 2.6.18-128.4.1.el5 #1 SMP Tue Aug 4 12:51:10 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux

Answer 1

The problem is that you built your new GCC incorrectly: on Linux you should use

./configure --prefix=/usr

The default installation prefix is /usr/local, which is why make install put gcc and g++ binaries into /usr/local/bin, etc.

What's happening to you now is that you compile and link using the new (symlinked) GCC 4.2.4, but at runtime your program binds to the old /usr/lib64/libstdc++.so.6 (version 6.0.8, instead of required 6.0.9). You can confirm that by running ldd build/ALPHA_SE/m5.opt: you should see that it uses /usr/lib64/libstdc++.so.6.

There are several fixes you could do.

env LD_LIBRARY_PATH=/usr/local/lib64 ldd build/ALPHA_SE/m5.opt

should show you that setting LD_LIBRARY_PATH is sufficient to redirect the binary to correct library, and

LD_LIBRARY_PATH=/usr/local/lib64 build/ALPHA_SE/m5.opt

should just run. You could "bake" this path into m5.opt binary by relinking it with -Wl,-rpath=/usr/local/lib64.

A more permanent solution is to fix the libraries the same way you fixed the binaries:

cd /usr/lib64 && mv libstdc++.so.6 libstdc++.so.6_bak &&
ln -s /usr/local/lib64/libstdc++.so.6 .

An even better solution is to reconfigure the new GCC with --prefix=/usr, and then make all install.