gb generate fails on no-go folders

[fzerorubigd]

Running gb generate on a folder that contain other folders with no .go inside them (like html/css/js assets) fails with

can't load package: package statics/swagger: no buildable Go source files in /path/to/statics/swagger

the job is done, but gb exit code is 1 and not zero. so I can not depend on output if there is actually an error in my command or its the folder without go code.

ps : Also it is nice to have -x -v and -n support just like the go tools.