Why -bash: /usr/bin/g++: cannot execute binary file?

simpatico$ /Developer/usr/bin/g++-4.2 -v
Using built-in specs.
Target: i686-apple-darwin10
Configured with: /var/tmp/gcc/gcc-5664~89/src/configure --disable-checking --enable-werror --prefix=/usr --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-transform-name=/^[cg][^.-]*$/s/$/-4.2/ --with-slibdir=/usr/lib --build=i686-apple-darwin10 --pr开发者_StackOverflow中文版ogram-prefix=i686-apple-darwin10- --host=x86_64-apple-darwin10 --target=i686-apple-darwin10 --with-gxx-include-dir=/include/c++/4.2.1
Thread model: posix
gcc version 4.2.1 (Apple Inc. build 5664)

simpatico$ /usr/bin/g++ -v
-bash: /usr/bin/g++: cannot execute binary file

I don't know of a command that proves that /usr/bin/g++ is an alias of /Developer/usr/bin/g++-4.2.

simpatico$ sudo gcc_select gcc42