It seems like dh_auto_install used to set INSTALL_ROOT (works in jessie), but now it doesn't, so the build fails in sid.
But it's easy to set INSTALL_ROOT, manually. Just add it to the call of dh_auto_install in debian/rules: --- a/debian/rules +++ b/debian/rules @@ -22,7 +22,7 @@ override_dh_auto_configure: ./configure --prefix=/usr override_dh_auto_install: - dh_auto_install + dh_auto_install -- INSTALL_ROOT=$(CURDIR)/debian/qconf mv debian/qconf/usr/bin/qconf debian/qconf/usr/bin/qt-qconf As qconf packaging is managed in git at github, I sent a pull request: https://github.com/tehnick/qconf-debian/pull/1