[buildd-tools-devel] Bug#403246: sbuild dependancy resolution fails when b-dep on A | B ; A uninstallable

[Jonathan Yu]

Using the newest version of sbuild in sid, I'm still having this issue.

I have read the discussion from the bug report log, but would like to
add this bit of an argument as to why alternative dependencies are
useful, and why sbuild should be able to resolve them.

Consider the case of Dual-Life modules in Perl. These are modules that
are released both in the Perl core, and released separately as a
standalone package. This strategy makes it possible to use core
modules with older versions of Perl.

Recently I came across this with the Test::Simple package, which
includes Test::More. Perl version 5.10.1 has updated this
(http://search.cpan.org/~dapm/perl-5.10.1/pod/perl5101delta.pod#Updated_Modules):

Test::Simple
    Upgraded from version 0.72 to 0.92.

I was upgrading a package that requires Test::Simple >= 0.80. This
means it can be satisfied either by:
 perl-modules (>= 5.10.1)
OR
 libtest-simple-perl (>= 0.80)

Without alternative dependencies, one's only choice would be to
upgrade libtest-simple-perl, or install it despite it being made
unnecessary by its inclusion as a core module (ie, installing it even
though it is already installed as part of perl-modules).

I still haven't figured out what can be done about this. I suppose for
now the only way to make it build at all is to use:
 libtest-simple-perl (>= 0.80)
as a dependency.

Build-Depends-Indep: libperl-minimumversion-perl,
libtest-minimumversion-perl, libpod-simple-perl (>= 3.07),
libtest-pod-perl (>= 1.26), libtest-cpan-meta-perl,
libtest-script-perl (>= 1.05), perl-modules (>= 5.10.1) |
libtest-simple-perl (>= 0.80)

perl-modules: non-matching version installed (5.10.0-25 ! >= 5.10.1)
Default version of perl-modules not sufficient, no suitable
alternative found. I probably should dep-wait this one.
Package installation not possible