Because this is top post being shown in Google search for problems with qdbusviewer and they persist also on 18.04 here is the solution:
1. Find an error message. In my case (even after installing default):
qdbusviewer: could not exec '/usr/lib/qt5/bin/qdbusviewer': No such file or directory
2. Find in which package is file being reported as missing:
$ apt-file search /usr/lib/qt5/bin/qdbusviewer qttools5-dev-tools: /usr/lib/qt5/bin/qdbusviewer
3. Install found package:
$ sudo apt install qttools5-dev-tools
Voila!
Because this is top post being shown in Google search for problems with qdbusviewer and they persist also on 18.04 here is the solution:
1. Find an error message. In my case (even after installing default):
qdbusviewer: could not exec '/usr/lib/ qt5/bin/ qdbusviewer' : No such file or directory
2. Find in which package is file being reported as missing:
$ apt-file search /usr/lib/ qt5/bin/ qdbusviewer dev-tools: /usr/lib/ qt5/bin/ qdbusviewer
qttools5-
3. Install found package:
$ sudo apt install qttools5-dev-tools
Voila!