qttools5-dev-tools depends on qttools5-dev-tools

[Alexey Bondarchuk <alexey.bondarchuk@aleax.me>]

I try to build qttools5-dev-tools from sources (source package
qttools-opensource-src from testing), but it depend on itself:

> apt-cache showsrc qttools5-dev-tools
> [skip]
> Package: qttools-opensource-src
> Binary: libqt5clucene5, libqt5designer5, libqt5designercomponents5, qdbus-qt5, libqt5help5, qttools5-dev, qttools5-private-dev, qttools5-dev-tools, qttools5->examples, qttools5-dbg, qttools5-examples-dbg, qttools5-doc, qttools5-doc-html
> Version: 5.1.1-1
> [skip]

So debuild (and pdebuild in clean chroot environment) can`t build it:
> dpkg-checkbuilddeps: Unmet build dependencies: qttools5-dev-tools (>= 5.1.1~)

How to build this package from source, if I haven't builded it in my system yet?