gdb fails to run ELF 64-bit program with “File format not recognized”

Question

I\'m trying to use GDB to debug (to find an annoying segfault). When I run:

gdb ./filename

from the command line, I get the following error:

Answer 1

The executable is 64-bit (x86-64) and the debugger is a 32 bit (i686-pc-linux) build. You may need to install a 64-bit (x86-64) version of the debugger.