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Ciaran McCreesh <ciaran.mccreesh@××××××××××.com> posted |
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20080826142044.28367055@××××××××××.com, excerpted below, on Tue, 26 Aug |
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2008 14:20:44 +0100: |
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|
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> On Tue, 26 Aug 2008 06:39:38 +0000 (UTC) Duncan <1i5t5.duncan@×××.net> |
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> wrote: |
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>> But I think virtual works just fine for kde-base/kde, too, if one |
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>> simply reads it literally -- it's a virtual package in that it doesn't |
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>> install anything itself, even if it's a meta-package [...] |
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> |
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> So what does 'virtual' actually mean then, and how is it related to the |
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> defined behaviour of this property? |
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I'm unsure of whether that was intended to be a rhetorical question or |
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not, so taking it literally... |
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|
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According to kdict/WordNet: |
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|
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2: being such in essence or effect though not in actual fact |
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|
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Extending that to the technical/computing realm, again kdict, this time |
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FOLDOC and Jargon file: |
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|
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<jargon, architecture> (Via the technical term virtual |
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memory, probably from the term "virtual image" in optics) |
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|
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1. Common alternative to logical; often used to refer to the |
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artificial objects (like addressable virtual memory larger |
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than physical memory) created by a computer system to help the |
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system control access to shared resources. |
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|
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2. Simulated; performing the functions of something that isn't |
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really there. An imaginative child's doll may be a virtual |
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playmate. |
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|
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Opposite of real or physical. |
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|
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|
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So a virtual package would have the essence and effects of a real one |
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(dependencies and the like) but not be "real" in some way (here, zero- |
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install-cost, or more correctly, only the install cost of the |
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dependencies). |
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|
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More directly, a package that doesn't actually install anything itself, |
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only having dependencies that ensure other packages are installed. |
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|
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In original Gentoo usage, virtual packages didn't have ebuilds at all, |
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but referred to dependencies that several different packages could |
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provide, with the the profile generally specifying a default. Now many |
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of them have ebuilds, but the general idea of not installing anything |
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directly themselves, only thru dependencies, remains. This is equally |
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true of the original no-ebuild virtuals, those ebuilds in the virtual/ |
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categories, and various meta-packages such as kde and kde-meta. Thus, |
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they fit the broader defintion of "virtual" in a literal sense, |
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regardless of where they are located in the category tree. |
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|
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However, I like the idea someone else proposed as well. Move all these |
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packages into the virtual category. That could of course be expanded to |
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include java-virtuals if desired, since virtual is still part of the |
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category name. Either as a single category or as anything with "virtual" |
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in the category, this would make things easier for both the package |
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manager (making the property unnecessary) and the user, who would then |
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know on sight (in the tab-completion and in --pretend/ask as well as |
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various $PM messages) which packages were virtual. |
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|
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Putting all virtual packages in the virtual category/ies would certainly |
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simplify the task of explaining to confused users why removing say kde- |
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base/games wanted to remove virtual/kde (instead of kde-base/kde), but |
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wouldn't directly remove kdebase (tho emerge --depclean would then want |
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to do so, until the user did an emerge --no-replace kdebase, at least), |
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to use an example I saw in a different context recently. |
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|
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I therefore believe I like just moving them all to a *virtual*/ category |
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better, thus obviating the need for that particular property in the first |
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place. |
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|
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-- |
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Duncan - List replies preferred. No HTML msgs. |
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"Every nonfree program has a lord, a master -- |
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and if you use the program, he is your master." Richard Stallman |