Re: flow of things rules/debhelper

[Osamu Aoki <osamu@debian.org>]

On Wed, Apr 07, 2010 at 02:57:41PM +0200, Raphael Hertzog wrote:
> On Wed, 07 Apr 2010, Osamu Aoki wrote:
> > What is needed is documentation on dh_listpackages and its usage to sort
> > out binary-indep and binary-arch difference for override commands.
> > 
> > Otherwise, buildd may fail if they only install Build-Depends: (I vaguely
> > remember, they install Build-Depends-Indep: too.  But you never know.)
> 
> I think you are confusing issues here. For override commands, the -i and
> -a options of debhelper are implicitly passed through the environment
> variable DH_INTERNAL_OPTIONS, that't the only difference I know between
> overrides targets called in binary-indep vs binary-arch.
> 
> buildd only install Build-Depends but they also build packages with
> "dpkg-buildpackage -B" so that they call "debian/rules binary-arch"
> (and not binary or binary-indep). So everything is fine on that regard
> AFAIK.
> 
> The hack using dh_listpackages that you quote might not even be needed
> nowadays. If a commands receives -p<package> and has contradictory options
> in DH_INTERNAL_OPTIONS, it will do nothing just like expected:
> ┏rivendell:~/tmp/circuslinux-1.0.3
> ┗(522)$ DH_INTERNAL_OPTIONS="-i" dh_listpackages -pcircuslinux
> dh_listpackages: No packages to build.
> ┏rivendell:~/tmp/circuslinux-1.0.3
> ┗(523)$ DH_INTERNAL_OPTIONS="-a" dh_listpackages -pcircuslinux
> circuslinux
> ┏rivendell:~/tmp/circuslinux-1.0.3
> ┗(524)$ dh_listpackages
> circuslinux
> circuslinux-data

Well this only has Build-Depends:  There is no extra packages needed for
Build-Depends-indep:  

Yes for many dh_* command that, if a commands receives -p<package> and has
contradictory options in DH_INTERNAL_OPTIONS, it will do nothing just like
expected.  The install to package building phase drop unneeded action
automatically using this feature.

But are you sure this holds for dh_auto_build.  If buildd only install
Build-Depends and dh_auto_build initiate doc building using latex listed in
-indep, then we are in trouble.  As I understand, it usually run $(MAKE) for
any case.  So if doc package needs latex-thingy in Build-Depends-indep,
override_dh_auto_build needs to take care -i and -a issue providing separate
target to $(MAKE) = dh_auto_build as:

override_dh_auto_build:
        ifneq (,$(findstring one-for-arch, $(shell dh_listpackages)))
        dh_auto_build -- build-one-for-arch
endif
        ifneq (,$(findstring one-for-doc, $(shell dh_listpackages)))
        dh_auto_build -- build-doc
endif

We can not use conditional on DH_INTERNAL_OPTIONS here to change behavior of
override_dh_foo.  This is because, debhelper maintainer Joey Hess told me so.
He specifically pointed to this dh_listpackages.