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On Sun, 2005-03-06 at 19:40 +0200, Dan Armak wrote: |
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> It's a cool idea. What's missing in the proto-GLEP is an explanation of why |
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> you can't do this with a normal ebuild (that doesn't install any files), and |
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> need the new concept of metapackages. |
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The idea is that a metapackage, unlike a normal ebuild, doesn't exist in |
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the installed package db, and its deps are always inspected when it |
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turns up in the depgraph. That means that you avoid the situation where |
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you merge package A, which depends on virtual/x11, and then pulls in |
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xorg-x11. Then, for whatever reason, you unmerge xorg, and virtual/x11 |
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is still in the vdb, so the next app you merge that deps on it will |
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break. That was explained in the -dev thread I linked; I probably should |
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add an explanation into the GLEP. |
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> There's also the question of portage not checking RDEPENDs when unmerging, so |
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> you can unmerge a dep (and things will break) but you can't unmerge a package |
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> providing a virtual (portage will catch that). But the correct solution here, |
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> if we're going to modify portage, is to add generic RDEPEND checking support |
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> to emerge unmerge... |
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Allegedly the new dep resolver that's being worked on should handle |
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that... not sure if it'll get into the next portage release though. But |
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agreed, it is needed, and from what I've been given to understand should |
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handle this situation properly without too much extra effort. |
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> Also, the GLEP says: "On a side note, this system of metapackages would |
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> provide an implementation of 'package sets' as proposed in GLEP 21 [2]_." |
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> |
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> I don't see how that would happen. A package set exists to install all of a |
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> list of packages, while a virtual/metapackage exists to install one of a list |
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> of (often mutually exclusive) packages. These are very different goals. How |
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> would metapackages help with sets any more than ordinary ebuilds already do? |
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Since the metapackage has some arbitrary DEPEND string that has to be |
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met, there's no reason why this couldn't require all packages reckoned |
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to be part of a set, rather than one of the packages reckoned to provide |
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a virtual. |
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-- |
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