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On Mon, 23 Feb 2009 08:43:09 -0700 |
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Steve Dibb <beandog@g.o> wrote: |
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> Plus, I don't really grasp the whole "we have to source the whole |
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> ebuild to know the EAPI version" argument. It's one variable, in one |
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> line. Can't a simple parser get that and go from there? |
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Not true. This is entirely legal: |
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In pkg-1.ebuild: |
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EAPI="${PV}" |
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printf -v EAPI '%s' 4 |
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inherit foo |
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EAPI="2" |
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In foo.eclass: |
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EAPI="3" |
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And in this case, the package manager has to know that EAPI=2, and it |
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has to use EAPI 2's behaviour for performing the inherit. |
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In fact, it gets worse if you consider that future EAPIs will probably |
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allow per-package eclasses. So you could end up with this crazy |
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situation: |
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In pkg-1.ebuild: |
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require pkg |
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In cat/pkg/pkg.eclass: |
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EAPI="3" |
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In global pkg.eclass: |
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EAPI="2" |
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So here you can't even use a faked pre-source EAPI. If you assume EAPI |
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0 beforehand, the global pkg.eclass will be used, so EAPI will end up |
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as 2. But if you assume EAPI 3 beforehand, the per-pkg eclass will be |
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used, so the EAPI will end up as 3. |
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It gets even crazier if you put EAPI="2" in the per-pkg eclass and |
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EAPI="3" in the global one instead... |
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And whilst this is clearly a deliberate example of how to create |
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craziness, the only difference between this and the real world is that |
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the craziness is obvious here. The current rules really are this |
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complicated, and we can't retroactively fix them. |
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-- |
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Ciaran McCreesh |
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