Re: [gentoo-dev] RFC: Should preserve-libs be enabled by default?

2008-05-29 Thread Rémi Cardona

Marius Mauch a écrit :

So, do you think it should be enabled by default?


Does portage have a way to report which libraries it is keeping around 
because of preserve-libs ? If there's an easy way to figure that out, 
then enabling it by default is a very sane and sound idea.


Cheers,

Rémi
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Re: [gentoo-dev] RFC: Should preserve-libs be enabled by default?

2008-05-29 Thread Fabian Groffen
On 29-05-2008 08:54:48 +0200, Rémi Cardona wrote:
 Marius Mauch a écrit :
 So, do you think it should be enabled by default?

 Does portage have a way to report which libraries it is keeping around  
 because of preserve-libs ? If there's an easy way to figure that out,  
 then enabling it by default is a very sane and sound idea.

It does so after every merge IIRC, and you can also find them in a file
somewhere.


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Fabian Groffen
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Re: [gentoo-dev] RFC: Should preserve-libs be enabled by default?

2008-05-29 Thread Mike Auty

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Marius Mauch wrote:
| The purpose of this is to keep the system operational after library
| upgrades until all affected packages could be rebuilt and to simplify
| the process, not to avoid the rebuilds.

I couldn't find it mentioned in your email, but if portage is
effectively doing reference counts, what happens when its reference
count gets to 0?  Once no ebuilds rely on the old library is it removed
automatically, or do the you need to rebuild these message just go away?

Is there a way to have portage delete the libraries once it's sure
they're no longer necessary?  If so, is that done by rebuilding the
owning package itself, or by editing the owning pacakge's contents and
removing the old library?

Does @preserved-rebuild contain just the affected packages, or the
package containing the old library as well?  (i.e. Does an emerge
@preserved-rebuild ensure that the old library will no longer exist on
your system, or not?)

Basically, if I can safely replace revdep-rebuild with emerge
@preserved-rebuild then I'd be happy to keep it enabled.  If it's going
to leave cruft on the system (or then require manual rebuilds of
packages containing preserved libraries to clear out the cruft) then I'd
personally be inclined to turn it off and stick with revdep-rebuild...

Mike  5:)
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Re: [gentoo-dev] RFC: Should preserve-libs be enabled by default?

2008-05-29 Thread Arfrever Frehtes Taifersar Arahesis
2008-05-29 08:54:48 Rémi Cardona napisał(a):
 Does portage have a way to report which libraries it is keeping around 
 because of preserve-libs ?

portageq list_preserved_libs /

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Re: [gentoo-dev] RFC: Should preserve-libs be enabled by default?

2008-05-29 Thread Marius Mauch
On Thu, 29 May 2008 09:28:16 +0100
Mike Auty [EMAIL PROTECTED] wrote:

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 Marius Mauch wrote:
 | The purpose of this is to keep the system operational after library
 | upgrades until all affected packages could be rebuilt and to
 | simplify the process, not to avoid the rebuilds.
 
 I couldn't find it mentioned in your email, but if portage is
 effectively doing reference counts, what happens when its reference
 count gets to 0?  Once no ebuilds rely on the old library is it
 removed automatically, or do the you need to rebuild these message
 just go away?

They are removed automatically.

Marius
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[gentoo-dev] RFC: Should preserve-libs be enabled by default?

2008-05-28 Thread Marius Mauch
As portage-2.2 is about to be unmasked into ~arch soon (there is one
weird bug to solve before) it's time to ask for some input on one of
the important new features, FEATURES=preserve-libs.

(if you're already familiar with it you can skip this paragraph)
Simply said, when this feature is enabled portage keeps track of all
installed libraries and binaries linked against them, and if a package
upgrade would remove a library that's still in use portage will keep
the library around, owned by the new version and also registered in a
separate file. There is also an internal package set that can be used
to rebuild all packages linked against libraries preserved in this way,
and the user is notified after each emerge operation that he should do
that (the example is from an expat downgrade in case you wonder about
the versions): 
!!! existing preserved libs:
 package: dev-libs/expat-1.95.8
 *  - /usr/lib64/libexpat.so.1
 *  - /usr/lib64/libexpat.so.1.5.2
Use emerge @preserved-rebuild to rebuild packages using these libraries

The purpose of this is to keep the system operational after library
upgrades until all affected packages could be rebuilt and to simplify
the process, not to avoid the rebuilds.

Now the question is if this behavior should be enabled by default?

In the existing prereleases it has been enabled to get some real-world
testing, and it's been quite effective, though there are still a few
issues to be worked out (e.g. if libraries are moved between packages).
And no doubt a few more bugs will turn up over time.
Also it is not going to be a perfect solution against all runtime link
errors, but if enabled it should eliminate the need for revdep-rebuild
in most cases.
One concern raised by some people is that it might cause old libraries
with security issues to stay on the system for eternity even though
the package was upgraded, and eventually be preferred by new builds.
I can't rule this out completely but thinks it's very unlikely, as
preserved libraries are specially tracked and the user is notified
about their existance after every emerge operation (similar to glep42
news). And new builds shouldn't find them as the unversioned .so
symlinks ar going to point to the current versions.
So personally I'm not too worried about this concern becoming reality,
but I can understand if others are.

So, do you think it should be enabled by default?

Marius

PS: Obviously, if you haven't tested portage-2.2 yet, now would be a
good time.

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Re: [gentoo-dev] RFC: Should preserve-libs be enabled by default?

2008-05-28 Thread Donnie Berkholz
On 01:13 Thu 29 May , Marius Mauch wrote:
 One concern raised by some people is that it might cause old libraries
 with security issues to stay on the system for eternity even though
 the package was upgraded, and eventually be preferred by new builds.
 I can't rule this out completely but thinks it's very unlikely, as
 preserved libraries are specially tracked and the user is notified
 about their existance after every emerge operation (similar to glep42
 news).

Part of this should be addressable by keeping track of the version that 
installed them and checking it against the distributed GLSAs...

Thanks,
Donnie
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