There are a difference in our build layout. I have gumstix-oe as a sub directory in gumstix in my home directory. That is /home/alex/gumstix/gumstix-oe rather than ~/gumstix-oe. I do not know if that alone would make a difference.
The gumstix build comes with a full "Hello World" build, so be careful that you do not build gumstix's hello world. The .bb file for your Hello World calls all of the functions it needs to build an executable.