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On Wednesday 15 March 2006 16:13, Gustavo Sverzut Barbieri wrote: |
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> Hello, |
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> |
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> There is any provision for binary dependency on Gentoo/Portage? The |
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> way it works now is quite messy with things like revdep-rebuild. |
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> |
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> I have an idea to "solve" this problem: after software is build, you |
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> check which files it links (ldd binaries libraries) and check the used |
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> against installed packages. If a library is not provided by an |
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> installed package we could have a policy to inform user or just abort |
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> installation. |
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> |
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> Also, if we implement these dependencies in rpm-generator, we could |
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> just generate RPM packages and install it in the RPM-DB and let it |
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> handle these kind of things. |
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> |
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> With these in place emerge would handle the build stage (where it |
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> excels), but rpm would handle the binary installation and dependencies |
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> (where it excels). |
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|
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Solving this is not trivial. Basically suppose application X depends on |
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sys-libs/db-4.* |
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|
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This can be resolved by differently slotted libraries. We need to record |
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which one was actually used (not easy by itself, but more an issue of the |
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ebuild itself, if more than 1 candidate is available). But suppose that |
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we know that the application was compiled to use db-4.3.29. We must then |
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know that it is ok to replace the db-4.3.29 package with 4.3.30, but that |
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it isn't ok to replace it by 4.3.28 or 4.4.20. |
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|
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To make this things worse, the above example assumes that within a slot, |
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the libraries are binary compatible. There are examples of libraries that |
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are not. And what about a library whose interface is dependent on a third |
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library: B uses A, C uses B, but B exports A. So B is dependent on A, and |
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the binary package of C must record that B was compiled with A. |
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|
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In short, welcome to binary package hell. This is the reason that binary |
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distributions must use versions. Even debian. It is just very very hard |
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to fix these kinds of indirect dependencies. |
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|
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Paul |
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|
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-- |
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Paul de Vrieze |
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Gentoo Developer |
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Mail: pauldv@g.o |
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Homepage: http://www.devrieze.net |
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