Gentoo Archives: gentoo-dev

From: Alexis Ballier <aballier@g.o>
To: gentoo-dev@l.g.o
Cc: qa@g.o
Subject: [gentoo-dev] On the good usage of subslots
Date: Sat, 09 Feb 2013 12:15:15
1 Dear fellow developers,
3 I hope this will be trivial to most of you but after seeing bug #455900
4 and the vast majority of developers not even thinking twice before
5 sedding their dep strings, I believe this needs some attention.
7 What do subslots do: You set a subslot to a package and every time said
8 package subslot changes (e.g. with an update), others packages
9 depending on it with a := dep will be rebuilt. Nothing more, nothing
10 less.
12 Now, this solves a real problem: haskell, perl and ocaml packages need
13 to be rebuilt after updating their respective compiler/interpreter and,
14 in some cases, even after updating the libraries they use. Subslots
15 would make haskell-updater, perl-cleaner and ocaml-rebuild not needed
16 in the future.
18 You can also use subslots to notify an ABI change in a shared library,
19 in order to avoid having to use preserve-libs or run revdep-rebuild.
20 However, this week I had to rebuild webkit-gtk three or four times and
21 libreoffice twice...
22 If you want to notify ABI changes, then you should set subslot to
23 something representing the ABI, $PV as subslot is most certainly wrong
24 in that case. Subslot is *not* a substitute to checking your library
25 ABI, checking if its reverse dependencies work fine after the update,
26 and notifying upstream if something went wrong so they can make a quick
27 release fixing their mistake. Subslot is also *not* a substitute to
28 soname and ensuring ABI compatibility (at least forward) between
29 libraries with the same major. Using subslot only to be on the safe
30 side and forcing a rebuild of all the dependent packages because it is
31 too much work to check the ABI and work with upstream is, IMHO, a
32 serious QA issue.
34 Thank you for your attention,
36 Alexis.


Subject Author
[gentoo-dev] Re: On the good usage of subslots Michael Palimaka <kensington@g.o>
Re: [gentoo-dev] On the good usage of subslots Samuli Suominen <ssuominen@g.o>
Re: [gentoo-dev] On the good usage of subslots "Michał Górny" <mgorny@g.o>