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.
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
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
.