Re: [gentoo-dev] Re: On the good usage of subslots
-BEGIN PGP SIGNED MESSAGE- Hash: SHA256 On 09/02/13 07:52 AM, Alexis Ballier wrote: On Sat, 09 Feb 2013 23:38:35 +1100 Michael Palimaka kensing...@gentoo.org wrote: I even noticed some maintainers adding subslots dependencies on libraries that do not yet define subslots. This too seems reasonable, given that there would be no impact until the library defines a (sensible) subslot in the future. By the way, this could also be discussed: I did not check, but as far as I understand it subslot is equal to slot if not defined. When said library defines a subslot, the subslot will change and thus triggers a (likely useless) rebuild of your package setting a := dep. Alexis. That isn't so much of a concern, imo, as the sub-slot introduction (and therefore change) will most likely not occur on a library until that library is bumped (ie, when an upgrade occurs on the library and therefore also a rebuild of rdeps) -BEGIN PGP SIGNATURE- Version: GnuPG v2.0.19 (GNU/Linux) iF4EAREIAAYFAlEZENUACgkQ2ugaI38ACPDKtAD8CLuyIbPH7yhzYj0hsShlLgkU LJkJCrtnureSz9dyUPgA/R0GMc71Oys9K62E6p+Qye+xg1AQdP8iEj6IHSFhzv0+ =sxVB -END PGP SIGNATURE-
Re: [gentoo-dev] Re: On the good usage of subslots
On Sun, 10 Feb 2013 01:09:38 +1100 Michael Palimaka kensing...@gentoo.org wrote: On 9/02/2013 23:52, Alexis Ballier wrote: On Sat, 09 Feb 2013 23:38:35 +1100 Michael Palimaka kensing...@gentoo.org wrote: I even noticed some maintainers adding subslots dependencies on libraries that do not yet define subslots. This too seems reasonable, given that there would be no impact until the library defines a (sensible) subslot in the future. By the way, this could also be discussed: I did not check, but as far as I understand it subslot is equal to slot if not defined. When said library defines a subslot, the subslot will change and thus triggers a (likely useless) rebuild of your package setting a := dep. Alexis. Yeah. This behaviour can be avoided by introducing the explicit subslot only when the subslot would otherwise need bumping. I would not count on that as this would mean extra care has to be taken when adding a subslot. Alexis.
[gentoo-dev] Re: On the good usage of subslots
Hi, On 9/02/2013 23:15, Alexis Ballier wrote: Dear fellow developers, I hope this will be trivial to most of you but after seeing bug #455900 and the vast majority of developers not even thinking twice before sedding their dep strings, I believe this needs some attention. What is wrong with maintainers just updating their dependencies in this fashion? Surely the onus in this case is on package maintainers setting sensible subslots (which is indeed what you appear to be saying below)? I even noticed some maintainers adding subslots dependencies on libraries that do not yet define subslots. This too seems reasonable, given that there would be no impact until the library defines a (sensible) subslot in the future. What do subslots do: You set a subslot to a package and every time said package subslot changes (e.g. with an update), others packages depending on it with a := dep will be rebuilt. Nothing more, nothing less. Now, this solves a real problem: haskell, perl and ocaml packages need to be rebuilt after updating their respective compiler/interpreter and, in some cases, even after updating the libraries they use. Subslots would make haskell-updater, perl-cleaner and ocaml-rebuild not needed in the future. You can also use subslots to notify an ABI change in a shared library, in order to avoid having to use preserve-libs or run revdep-rebuild. However, this week I had to rebuild webkit-gtk three or four times and libreoffice twice... If you want to notify ABI changes, then you should set subslot to something representing the ABI, $PV as subslot is most certainly wrong in that case. Subslot is *not* a substitute to checking your library ABI, checking if its reverse dependencies work fine after the update, and notifying upstream if something went wrong so they can make a quick release fixing their mistake. Subslot is also *not* a substitute to soname and ensuring ABI compatibility (at least forward) between libraries with the same major. Using subslot only to be on the safe side and forcing a rebuild of all the dependent packages because it is too much work to check the ABI and work with upstream is, IMHO, a serious QA issue. Thank you for your attention, Alexis. Best regards, Michael
Re: [gentoo-dev] Re: On the good usage of subslots
On Sat, 09 Feb 2013 23:38:35 +1100
Michael Palimaka kensing...@gentoo.org wrote:
Hi,
On 9/02/2013 23:15, Alexis Ballier wrote:
Dear fellow developers,
I hope this will be trivial to most of you but after seeing bug
#455900 and the vast majority of developers not even thinking twice
before sedding their dep strings, I believe this needs some
attention.
What is wrong with maintainers just updating their dependencies in
this fashion? Surely the onus in this case is on package maintainers
setting sensible subslots (which is indeed what you appear to be
saying below)?
If subslot does not represent ABI then it's wrong to set such := deps:
By setting them you are forcing your users to needlessly rebuild your
package.
Think about glib: gobject-introspection needs to be rebuilt after each
glib update. glib maintainers will likely want glib to have ${PV} as
subslot and let gobject-introspection := depend on it. Packages that do
not break with minor updates of glib (ie 99% of them) should not :=
depend on glib, even if it has a subslot.
What I wanted to say could be summarized as: Please define what your
subslot means when you define one and please check if that is the
meaning you want to give it when you set := deps.
Alexis.
Re: [gentoo-dev] Re: On the good usage of subslots
On Sat, 09 Feb 2013 23:38:35 +1100 Michael Palimaka kensing...@gentoo.org wrote: I even noticed some maintainers adding subslots dependencies on libraries that do not yet define subslots. This too seems reasonable, given that there would be no impact until the library defines a (sensible) subslot in the future. By the way, this could also be discussed: I did not check, but as far as I understand it subslot is equal to slot if not defined. When said library defines a subslot, the subslot will change and thus triggers a (likely useless) rebuild of your package setting a := dep. Alexis.
[gentoo-dev] Re: On the good usage of subslots
On 10/02/2013 00:47, Samuli Suominen wrote: On 09/02/13 14:15, Alexis Ballier wrote: Dear fellow developers, I didn't find anything to reply directly here, so sorry for stealing this message. I just wanted to point out that people have lately been adding deps like: media-libs/libpng:= dev-libs/openssl:= That is wrong as it completely ignores the SLOTting of these packages. They need to be: media-libs/libpng:0= dev-libs/openssl:0= As in, before you add any subslotting to any library, you need to check for it's binary-only SLOTs! Thanks, Samuli Is there a difference in behaviour between 'media-libs/libpng:=' and 'media-libs/libpng' with no slot information at all?
[gentoo-dev] Re: On the good usage of subslots
On 9/02/2013 23:52, Alexis Ballier wrote: On Sat, 09 Feb 2013 23:38:35 +1100 Michael Palimaka kensing...@gentoo.org wrote: I even noticed some maintainers adding subslots dependencies on libraries that do not yet define subslots. This too seems reasonable, given that there would be no impact until the library defines a (sensible) subslot in the future. By the way, this could also be discussed: I did not check, but as far as I understand it subslot is equal to slot if not defined. When said library defines a subslot, the subslot will change and thus triggers a (likely useless) rebuild of your package setting a := dep. Alexis. Yeah. This behaviour can be avoided by introducing the explicit subslot only when the subslot would otherwise need bumping.
Re: [gentoo-dev] Re: On the good usage of subslots
On 02/09/2013 06:05 AM, Michael Palimaka wrote: Is there a difference in behaviour between 'media-libs/libpng:=' and 'media-libs/libpng' with no slot information at all? I don't know if you phrased your question as intended. Anyway, yes, the difference is that one with the slot-operator will trigger rebuilds when the SLOT or sub-slot changes. -- Thanks, Zac
[gentoo-dev] Re: On the good usage of subslots
On 10/02/2013 03:06, Zac Medico wrote: On 02/09/2013 06:05 AM, Michael Palimaka wrote: Is there a difference in behaviour between 'media-libs/libpng:=' and 'media-libs/libpng' with no slot information at all? I don't know if you phrased your question as intended. Anyway, yes, the difference is that one with the slot-operator will trigger rebuilds when the SLOT or sub-slot changes. You are right, I was not very clear, sorry about that. Samuli talked about not forgetting to add the primary slot when adding a subslot dependency. Does the behaviour there differ compared to omitting the slot when there is no subslot dependency? Eg. He wrote we should use 'media-libs/libpng:0=', but pre-subslots, the :0 was often (incorrectly?) omitted.
Re: [gentoo-dev] Re: On the good usage of subslots
On 09/02/13 18:36, Michael Palimaka wrote: Eg. He wrote we should use 'media-libs/libpng:0=', but pre-subslots, the :0 was often (incorrectly?) omitted. I've at least been adding :0 to many packages, openssl, tiff, libpng ... ... pretty much ever since the libpng 1.4 upgrade problem in the past that reminded me that if something is possible, users will do it people masked =media-libs/libpng-1.4 and they only got the :1.2 binary-only SLOT installed and ended up with no headers so having :0 forces the headers be there, and people don't get confused (at least if you read portage's output correctly)
Re: [gentoo-dev] Re: On the good usage of subslots
El sáb, 09-02-2013 a las 18:39 +0200, Samuli Suominen escribió: On 09/02/13 18:36, Michael Palimaka wrote: Eg. He wrote we should use 'media-libs/libpng:0=', but pre-subslots, the :0 was often (incorrectly?) omitted. I've at least been adding :0 to many packages, openssl, tiff, libpng ... ... pretty much ever since the libpng 1.4 upgrade problem in the past that reminded me that if something is possible, users will do it people masked =media-libs/libpng-1.4 and they only got the :1.2 binary-only SLOT installed and ended up with no headers so having :0 forces the headers be there, and people don't get confused (at least if you read portage's output correctly) Wouldn't be better to force (via repoman) people to set exact slot (or :* if packages work for all slots) to prevent problems like this and future breakages could appear when SLOT if bumped and rdeps are not fixes to depend on needed slot? signature.asc Description: This is a digitally signed message part
