Im programming with libxml++ library which is a C++ wrapper for libxml2 C library. My program compile ok and generates the executable, only when i run it, i get the following error:

/usr/local/pdc/pdc: symbol lookup error: /usr/local/pdc/pdc: undefined symbol: _ZN5xmlpp15SchemaValidatorC1Ev


then i did "ldd -r ./pdc" and resulted
[root@Labplan-39 pdc]# ldd -r pdc
linux-gate.so.1 => (0xb7f01000)
libxml++-2.6.so.2 => /usr/lib/libxml++-2.6.so.2 (0xb7ed6000)
libxml2.so.2 => /usr/lib/libxml2.so.2 (0x41f5f000)
libglibmm-2.4.so.1 => /usr/lib/libglibmm-2.4.so.1 (0xb7e84000)
libgobject-2.0.so.0 => /lib/libgobject-2.0.so.0 (0x419d7000)
libglib-2.0.so.0 => /lib/libglib-2.0.so.0 (0x418db000)
libpthread.so.0 => /lib/libpthread.so.0 (0x41841000)
liblxrt.so.1 => /usr/lib/liblxrt.so.1 (0xb7e75000)
libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x41a5f000)
libm.so.6 => /lib/libm.so.6 (0x41816000)
libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x41899000)
libc.so.6 => /lib/libc.so.6 (0x416b4000)
libsigc-2.0.so.0 => /usr/lib/libsigc-2.0.so.0 (0xb7e6f000)
libdl.so.2 => /lib/libdl.so.2 (0x4180f000)
libz.so.1 => /lib/libz.so.1 (0x4185c000)
libgmodule-2.0.so.0 => /lib/libgmodule-2.0.so.0 (0x41dcf000)
/lib/ld-linux.so.2 (0x41695000)
undefined symbol: _ZN5xmlpp15SchemaValidatorC1Ev (./pdc)

im not sure what to do now... never got this kind of error in runtime. Does anyone knows anything about this particular symbol or some documentation about symbols, so i can try to solve this? Thanks in advance!

Hi

You seem to have a library mismatch. I. e. one of the library headers you include in your program, defines a symbol that you reference in your program, BUT, when ran against the library referred to be the specific header, the symbol does not exist.

This usually happens only with dynamic (.so) libraries - i. e. some .so library you refer to has changed versions or is an incorrect version for the headers / symbol defs you are using to work with that library.

This sometimes happens with an auto-update of the library maybe changing the library .so itself, but not updating the headers associated with that library (and that are used by you).

How can i see if .so libraries and the headers are from the same version?

nevermind, i figured out. I had an old library installed, which was holding the .so libraries that needed to be updated. Once i did, the symbols resolved and everything works fine now! Thank you very much for your help