Re: [gentoo-dev] Reverse use of Python/Ruby versions

[William L. Thomson Jr.]

On Mon, 10 Apr 2017 13:38:58 +1200
Kent Fredric <kentnl@g.o> wrote:
>
> When you reverse this, you introduce a situation where adding a new
> version across the board creates a new skeleton-tree of support.

FYI, this is how it is when a new Java JDK comes out. When 1.5 came
out, if 1.4 code had issues compiling, the package was addressed. The
same thing can happen any time a new version comes out.

The impact most times is minimal. Unless there are wide sweeping
changes. Which is pretty rare in any language.

> And when you find something that *doesnt* work, you may have to
> recursively mark its *dependents* as "non-working" to avoid a
> dependency graph breakage.

This has never been the case with Java.

If package A requires version X, but B Y, then B builds with Y as its
pulled in as a dep. while A proceeds to build with X.

Where this is different for Python, Ruby, and also Perl. They all
install files into a directory based on version. You may have multiple
copies in each, vs one. Perl does not have targets, nor does Java.

> This is the sort of thing that makes life hell, for both developers
> and users.

The present system is a PITA for users. Fiddling with adding/removing
targets for Python/Ruby. In addition to selecting which for the system.
All these same problems exist for Java, with the exception of
installation locations as mentioned.

> I could be barking up the wrong tree, buy the python team could give a
> better idea of what that would look like in practice than me.

I have direct experience in this. I am experiencing some of this now
with JDK 9. It is different regarding Python and Ruby. It would be up
to those teams. But I do think the entire TARGETS aspect needs to be
revisited.

No one likes adding/removing TARGETS. That is a waste of anyone's time.
Much less developers adding/removing targets from ebuilds.

-- 
William L. Thomson Jr.