First make sure you follow the build instructions here, which including make deps gen to generate the files required to compile your code:
Second make sure you do not have old version of go-bindata or go-bindata-assetfs. Also make sure you do not have old copies of these binaries in your PATH.
Please note there are no known issues building Drone. The last build from 2 hours ago executed inside a vanilla golang image was successful. If there were build errors this would have failed. http://beta.drone.io/drone/drone/886