Bug#670955: pytango: FTBFS when not building -doc package: dh_sphinxdoc bombs out

[Aaron M. Ucko]

Source: pytango
Version: 7.2.3-1
Severity: serious
Justification: fails to build from source (but built successfully in the past)

Builds of pytango (as on the autobuilders) only covering its
architecture-dependent main package are failing:

     dh_install -a
     dh_installdocs -a
     dh_sphinxdoc -a
  dh_sphinxdoc: Sphinx documentation not found
  make: *** [binary-arch] Error 2

Could you please arrange to run dh_sphinxdoc only when building
pytango-doc?  You can test this change by running dpkg-buildpackage
(or your favorite wrapper) with the -B flag.

Thanks!