Bug#823918: apt-get --solver dump doesn't add Preferences field to edsp file

[Pietro Abate <pietro.abate@inria.fr>]

One more thing about this.

On 10/05/16 15:09, David Kalnischkies wrote:
> The preferences string is missing as it isn't sent – and it isn't sent because it
> doesn't apply to the specified solver: You requested 'dump' to resolve it, but
> the preferences string is for 'aspcud'.

this works as expected : 

APT_EDSP_DUMP_FILENAME=/tmp/dump.edsp apt-get -s --solver dump -o
'APT::Solver::Strict-Pinning=false' -o
'APT::Solver::dump::Preferences=-removed,-changed,-new,-count(solution,APT-Release:=/experimental/)'
build-dep qgis

where now the name of the solver and the preferences matches.

However if we read the spec carefully, the Preferences field is
associated to APT::Solver::Preferences

- **Preferences:** a solver-specific optimization string, usually
  coming from the `APT::Solver::Preferences` configuration option.

Using this command line : 

APT_EDSP_DUMP_FILENAME=/tmp/dump.edsp apt-get -s --solver dump -o
'APT::Solver::Strict-Pinning=false' -o
'APT::Solver::Preferences=-removed,-changed,-new,-count(solution,APT-Release:=/experimental/)'
build-dep qgis

nothing is passed in the edsp... 

I interpret this as APT::Solver::Preferences is a general
configuration parameter passed to the edsp doesn't matter the solver
used and APT::Solver::$solver::Preferences will be used only for a
specific solver.