Wednesday, March 09, 2011

skipping incompatible in /usr/lib64

I was building a 32-bit executable on a 64-bit machine, using the -m32 switch, and thought I knew how to deal with this error from the g++ or gcc compiler.

/usr/bin/ld: skipping incompatible /usr/lib64/ when searching for -lelf
/usr/bin/ld: skipping incompatible /usr/lib64/libelf.a when searching for -lelf
/usr/bin/ld: cannot find -lelf

I checked the link line for any binaries that might be 64-bit by running the file command, as in "file tau_run.o". They all looked 32-bit. I checked my LIBRARY_PATH environment variable, which tells the linker in which directories to find libraries.

The problem turned out to be not that the compiler was looking in the wrong place but that it was looking for the a file that did not exist. The dyninstAPI library has a file called, but they did not include a link from to, which is what the compiler wants to find. The compiler was doing a great job of rejecting 64-bit libraries and its error message was actually rather clear that it could not find the -lelf it was looking for.

As usual, HTH.