Submit/cups update

[MarcWeber]

This pull request consists of two patches:

1. gutenprint CVS (could be useful some time)
2. The more important patch introduces a second "cups-1.6.nix" module and nixpkgs changes which allow to print with cups-1.6 and 1.7. Have a look at the commit's description for details

[MarcWeber]

Setting LogLevel to debug or debug2 and commenting syslog lines might be useful. You'll get logs at /var/log/cups/*

[peti]

-1

I don't want the experimental non-standard "versionedDerivation" all over the place in those vital expressions.

[MarcWeber]

I don't like you calling it "experimental'. Creating a third "open issue" wiki page discussing all views would be the way to go. I agree that there are different views on this topic. Good old news: Its trivial to rewrite. If you look closely at the commit there are still many things to be fixed. Eg printing .ps files does not work. There is an open question whether we want to support both versions till we know that the knew one pleases everyone and all use cases etc. The perfect solution would introduce /etc/cups and /etc/cups-new so that you can switch easily. So there is much more to discuss than just "versionedDerivation" which really is handy if you want try many versions fast. So consider assisting with those additional topics, too.

[domenkozar]

Could you summarize the changes in pull request? That way pull request looks more attractive to be reviewed :)

[MarcWeber]

I assume github does not send updates, so I'm adding a comment telling that I've changed the description to contain a summary. The important description can be found in the cups-1.6-1.7 commit.

[domenkozar]

Thanks!

[vcunat]

versionedDerivation: is there any reason in this case to actually have other than the latest version in nixpkgs? Having just one would simplify the expression and maintenance.

(I originally thought this has been merged already, but I don't see it in master yet.)

[MarcWeber]

@vcunat: Please not that its getting harder to maintain because the modules now build custom cups related packages using deep override. So in the end versionedDerivation does not make a big difference IMHO.

As I said previously this is "work in progress" and we can change details. Its more important that we fix the remaining ps printing issue, printing test pages and get more testers.
See cupsPackages in old/new module to see the "deep overriding mess".
However its the only way I found to achieve a goal: allow testing different cups versions.

[peti]

Marc, you always say that you're willing to change details about the
expression, but the fact of the matter is that you never actually do!
The concerns about use of "versionedDerivation" have come up several
times now, but as far I can observe you don't take those concerns
seriously. You invariably end up dismissing other people's concerns as
pointless.

As far as I am concerned, I have zero incentive to review your work,
because experience has taught me that nothing I'll say about the
expression is going to have any observable effect on you. I'm rather
baffled why keep opening pull requests that seem to ask for other
people's opinion when in fact you don't seem to value other people's
opinion anyway.

[MarcWeber]

1. Why do I "keep sending pull requests"? Because my pull requests do solve
   problems thus I think they could be useful to others.
   Rewriting the versionedDerivation could be done in 5min.
   Coming up with the patch and testing that printing pdf files work (tool chain
   changed) has been more work.

I consider fixing the remaining issues more important:

• make print ps files work
• make printing test pages work
• think about whether we want to support older / newer cups for a
  while and how to do so) more important.

Compared to this the versionedDerivation usage is peanuts.
I also find a general discussion about whether nix language is powerful enough compared to guix more important. But that's my view - of course I'm fine with you having a different view.

Arguments like "you always" are bad style and unfair. Give references.
"you don't seem to value other people's opinion"
The simple "firebird service" is a counter example. I did listen.
A second proof that I do listen to what you do can be found in my reply
on the mailinglist pointing to your Haskell library. I'm not ignoring you nor
your words. I do make a difference between "is important" and "is not important
enough to care about at the moment"

So I don't think this is most important issue about nixos/nixpkgs/...
Anyway I've added this issue to this wiki page. So consider taking the time
adding your arguments why you feel bad about using versionedDerivation in such
simple cases. This way we have a pro/con list to refer to in the future:
https://nixos.org/wiki/Open_issues:derivation_styles

[shlevy]

I think the current policy on versionedDerivation and things like it is pretty clear for now. Feel free to reopen this if the policy changes or you decide to rewrite it with different versions in different package expressions.