Error: conflicting Ddoc and obj generation options

[anarcher]

I'm newbie for D.

I have tried build with custom library but the build is failed.

ubuntu at 9ffb916910cd:~/dshttpd$ dub
Building configuration "application", build type debug
Compiling...
Error: conflicting Ddoc and obj generation options
Error: DMD compile run failed with exit code 1

What's means "Error: conflicting Ddoc and obj generation options" 
?

Thanks for read.