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Hi everyone! |
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Some weeks ago [1] portage changed its behavior regarding what gets |
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stored as *DEPEND in the vdb. The curret behavior is to store the |
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*DEPEND variables with evaluated use conditionals. That is, if the |
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package has DEPEND="foo? ( cat/pkg2 )", either DEPEND="cat/pkg2" or |
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DEPEND="" end up in the vdb, depending on the state of the use flag 'foo'. |
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The old behavior was to store the unevaluated string. In the example |
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above DEPEND="foo? ( cat/pkg2 )" would have been stored in the vdb. |
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I propose to revert back to the original behavior. |
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What is the proposed change good for? |
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I see two reason. The first one more ideological and reads: "Don't throw |
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away information for no good reason". I say for no good reason, because |
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the evaluated value is easy to compute for users of the portage api, |
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where the unevaluated value is lost. |
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The second reason is that I want it to detect cases where the *DEPEND |
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variables have been changed without rev bump. To do this I want to |
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compare the *DEPEND string of the ebuild and the installed package. |
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Why can't you use the evaluated *DEPEND string? |
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Form time to time ebuilds get use flags added to IUSE without rev bump. |
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If the new use flags are used in *DEPEND variables and I evaluate the |
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use conditionals based on the enabled use flags of the installed |
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package, I'll always treat the newly added use flag as disabled. The |
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problem is that this might be wrong. |
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Consider this example: |
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installed package: |
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IUSE="" |
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RDEPEND="" |
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ebuild: |
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IUSE="some_feature" |
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RDEPEND="some_feature? ( cat/pkg2 )" |
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Assume the RDEPEND of the installed package is wrong, that is it should |
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have had cat/pkg2 in RDEPEND. After the maintainer noticed that, he |
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added a flag to disable the feature that needs cat/pkg2. Since |
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some_feature will be treated as disabled when the use conditionals in |
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the ebuild's RDEPEND are evaluated, RDEPEND will look unchanged. That |
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means portage won't pick up the change when it should. |
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Someone might come up with some logic to detect new use flags in |
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*DEPEND, but this looks like a hack to me. The clean solution is to |
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store the unevaluated string. |
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Question is: Does anyone have a good argument to not use the old |
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behavior again? |
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Sebastian |
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|
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[1] commit e6be6590e99522f9be69e2af8eff87919d9bf31f on 2010-02-14 |
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