Bug#971720: tumbler FTCBFS: gtk-doc runs host code

[Helmut Grohne <helmut@subdivi.de>]

On Wed, Oct 07, 2020 at 09:37:17PM +0200, Yves-Alexis Perez wrote:
> On Mon, 2020-10-05 at 20:25 +0200, Helmut Grohne wrote:
> > +       dh_auto_configure -- --$(if $(filter tumbler-common,$(shell
> > dh_listpackages)),en,dis)able-gtk-doc
> 
> Hi Helmut, thanks for the report. Is there not a nicer way to detect from
> debian/rules that we're running a cross build or something? It might just be
> aesthetics, but I'm not sure I really like the above line =/

There are ways to check whether we're running a cross build. The code
snippet above does not do that however. It checks whether the
tumbler-common package is part of the build, which really is the thing
we care about here. It does fix cross builds, but really what it says
is: Enable gtk-doc iff tumbler-common is being built.

The method used here is a quite common pattern. You can easily find lots
of users:
https://codesearch.debian.net/search?q=filter.*dh_listpackages&literal=0

You do have a point in that it is a little difficult to understand.
Would it help to write it more verbosely?

DO_PACKAGES:=$(shell dh_listpackages)

ifeq (,$(filter tumbler-common,$(DO_PACKAGES)))
CONFIGURE_ARGS += --disable-gtk-doc
else
CONFIGURE_ARGS += --enable-gtk-doc
endif

override_dh_auto_configure:
	dh_auto_configure -- $(CONFIGURE_ARGS)

Helmut