----- Original Message -----
On Thu, 29 Jan 2015 09:39:28 -0500 (EST)
Bohuslav Kabrda <bkabrda(a)redhat.com> wrote:
> Not sure about it being the default, but we've been testing it in
> DevAssistant for dependency installation on Python 3 and never
> encountered any problems. I was also contacted by dnf maintainer with
> a question on how to switch "dnf" to use
> "python3-dnf" (package-wise), so I guess that's what will be done for
> F22 (but that's just my guess, dnf maintainer would have to comment
> here).
See the thing there that makes my teeth itch is: dnf has been
massively great about having a long on-ramp. It appeared, it didn't
replace yum, it let people try it out and report bugs, there was a long
time of testing. Thats all great. But now, we switch it to dnf-3 and...
that has not had years of running in rawhide and other releases, it has
not had people testing it and reporting bugs. While the code overlap
could be pretty large, I am willing to bet a shiny us dollar that there
are some python 3 specific bugs lurking in it.
So, we turn on this not very tested path and immediately try and use it
as default in anaconda and a new release. What happened to our nice
long ramp? Or any ramp?
I just had a quick IRC chat with DNF maintainer and he said we still wants to switch to
py3 for F22.
> > Even still, that hinges on DNF being the default package
manager in
> > F22. There are some concerns that it won't make it due to rel-eng
> > tooling used to compose the images, etc. If that's the case, yum
> > will still be required.
>
> Required, yes, but we'll still have tons of packages built with
> Python 2. I never said that porting rel-eng tooling is the goal for
> F22.
Might be good to note that on the change page:
We will not be replacing python2 entirely, it and packages that depend
on it will still be available for now.
Doesn't [1] say it?
> So if more minimal is minimal buildroot, then we can achieve
that,
> since it only has python-libs because of gdb and gdb can be rebuilt
> with Python 3 (upstream source is compatible). If that means minimal
> cloud image, then we can do it (we're waiting for the cloud-init
> folks to accept the py3 patches, which should happen any time now).
> If that means content from fedora-live-base.ks, then we can do pretty
> much everything, except of samba (I think) - and Petr Viktorin is
> doing some talking to people to get rid of samba from this config,
> because it seems to be unnecessary there.
ok. So, perhaps we should have a change around this for f22, but it
should be: Python 3 migration improvements or something, not
'default' ?
Yeah, as noted by Stephen Smoogen, I think the problem is communication here. Judging from
reactions of people who I talked to, everyone takes it as "FESCo thinks that Python 3
is not ready and not the way to go right now". That's also what I thought when I
read simple "defer this to F23". After these conversations here I'm starting
to understand that this is not a message that FESCo meant to send. "Python 3
migration improvements" sounds about right to me and seems to send a better message
than just deferring to F23.
Can someone from FESCo comment on this? If this sounds ok, shall I create a change page
for it?
> Considering all the information mentioned above and assuming
Anaconda
> makes it, I'd say it should be perfectly possible to declare Python 3
> the default. As for the packages that are not in the minimal
> installs, I can always open bugs for them before beta and only those
> maintainers who believe it to be safe can switch.
Yeah, so if anaconda switches we get:
* anaconda switches to dnf (this is already done in rawhide after last
branch point, so I think it's quite safe/doable).
* anconda switches to dnf-3 (if we land that change. It's gotten 0
testing that I know of).
As I noted above, DevAssistant devels have been using python3-dnf for quite some time now
without any issues. I've written couple of scripts using python3-dnf and run them
regularly without any issue. I even replaced "#!/usr/bin/python" by
"!#/usr/bin/python3" in /usr/bin/dnf some time ago and everything still works
(how ugly is that? :)). I know, that's not extensive testing, but it's certainly
not zero.
* anconda switches to python3 (it's almost ready, but no telling
what
issues we will hit, it's not even landed yet).
Should we toss in a UI redesign so we can have Fedora 18 again?
(sorry, that was rude of me)
Why not :)
Wouldn't it be safer to defer dnf-3 and anaconda-py3 for next
cycle,
but make those changes in rawhide after the branch point? Then they
would actually get months of shake out...
kevin
I'd say we should leave this up to developers of DNF and Anaconda. They're the
best ones to say whether they're ready or not.
Slavek
[1]
http://fedoraproject.org/wiki/Changes/Python_3_as_Default#Upgrade.2Fcompa...