out-of-date reason (was: Tasks list order not consistent with execution order)

[Eduardo Schettino]

On Wed, Dec 17, 2014 at 2:10 AM, Tom Varga <tomvarga@gmail.com> wrote:

However, I have a possibly related question.

Is there a way to determine 'why' a specific task is out-of-date and needs to be rebuilt?

Assuming that the new dry-run works well, I still think there is a need to be able to ascertain why a task is out-of-date.

Is a file_dep new or missing for the requested task or a task_dep?  Or, are one or more targets missing or old?

With a fairly deep task dependency tree, it becomes really difficult to figure out why a task needs to be rebuilt.

It's often the case where simply re-building a bunch of tasks could be extremely costly in time and before committing to doing, I'd like to know why it needs to be re-done.

Right now, I'm thinking about writing a post-process on dumpdb output, but I don't think that there's enough info there to figure out if, for example, a target is missing.

Maybe this capability might eventually be a 'why-run' option. :)

What do you think?

Thanks,

-Tom

Hi Tom,

Yes. Showing some info on why a task is out-of-date is definitely important and missing in doit...

I think the best way would be to make this information available to reporters...

Than it would be a matter of just implementing a new reporter without the need for a new command.

I also planned to optionally display this on `info` command.

Regards,

  Eduardo