[Nix-dev] Underspecified 'disabled' attributes in python-packages.nix

[Peter Simons]

Hi Domen,

 >     in job ‘python33Packages.almir.x86_64-linux’:
 >     Package ‘python3.3-Beaker-1.6.4’ in
 >     ‘/nix/store/vr71jj15vk57p0mb85annpszswhhf7f4-git-export/pkgs/development/python-modules/generic/default.nix:57’
 >     is marked as broken, refusing to evaluate.
 >
 > The error you are seeing is because you changed the 'disabled'
 > attribute to behave as the package is broken in [79a5fec9].

actually, no, that is not true.

I changed the "disabled" attribute to set "meta.broken" instead of
throwing an error, because Hydra knows about meta.broken and does not
emit an error for packages that have this attribute set. All the errors
you currently see in [1] were there long before my change, and in fact
the plethora of evaluation errors from Python packages was what
motivated that change in the first place!

After that change, all packages that set "disabled" we filtered from the
jobset and thus no longer produced an evaluation error. The remaining
errors you see now are the from packages that *don't* set the "disabled"
attribute.


 > I'm reverting [79a5fec9] and sequential commits as they don't improve
 > the situation,

The commit *does* improve the situation because it removed a few hundred
evaluation errors from the Hydra error page. If you revert it, then
those errors will be back, which is highly undesirable in my humble
opinion.

Generally speaking, I'm somewhat offended by this practice of announcing
that you'll revert my commits (and then doing it without giving me a
chance to state my point of view). It's great for you that a few hundred
evaluation errors on Hydra don't seem to bother you, but they do bother
me, and I don't get the impression that you take that legitimate
interest of mine seriously.


 > the errors are still visible on Hydra evaluation tab, but they are
 > lying to the user that a package is broken whereas it's only not
 > supported.

It would be nice to have "meta.broken" accept an error message string
that's used to report the failure (with the boolean "true" defaulting to
the error error message we currently have). That way, it would be
possible to give the user more nuanced feedback about the reasons why a
certain package could not be installed.

Best regards,
Peter


[1] http://hydra.nixos.org/jobset/nixpkgs/trunk#tabs-errors