| 1 |
peper 08/01/05 02:42:59 |
| 2 |
|
| 3 |
Modified: gleps.xml |
| 4 |
Added: glep-0055.html |
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Log: |
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Add GLEP 55 html. |
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|
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Revision Changes Path |
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1.13 xml/htdocs/proj/en/glep/gleps.xml |
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|
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file : http://sources.gentoo.org/viewcvs.py/gentoo/xml/htdocs/proj/en/glep/gleps.xml?rev=1.13&view=markup |
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plain: http://sources.gentoo.org/viewcvs.py/gentoo/xml/htdocs/proj/en/glep/gleps.xml?rev=1.13&content-type=text/plain |
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diff : http://sources.gentoo.org/viewcvs.py/gentoo/xml/htdocs/proj/en/glep/gleps.xml?r1=1.12&r2=1.13 |
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|
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Index: gleps.xml |
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=================================================================== |
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RCS file: /var/cvsroot/gentoo/xml/htdocs/proj/en/glep/gleps.xml,v |
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retrieving revision 1.12 |
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retrieving revision 1.13 |
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diff -u -r1.12 -r1.13 |
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--- gleps.xml 19 Dec 2007 04:11:00 -0000 1.12 |
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+++ gleps.xml 5 Jan 2008 02:42:59 -0000 1.13 |
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@@ -1,5 +1,5 @@ |
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<?xml version='1.0' encoding="UTF-8"?> |
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-<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/proj/en/glep/gleps.xml,v 1.12 2007/12/19 04:11:00 antarus Exp $ --> |
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+<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/proj/en/glep/gleps.xml,v 1.13 2008/01/05 02:42:59 peper Exp $ --> |
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<!DOCTYPE gleps SYSTEM "/dtd/gleps.dtd"> |
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|
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<gleps> |
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@@ -166,5 +166,8 @@ |
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<glep file="glep-0054.html" id="54" type="S" status="D"> |
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scm package version suffix |
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</glep> |
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+<glep file="glep-0055.html" id="55" type="S" status="D"> |
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+ Use EAPI-suffixed ebuilds (.ebuild-EAPI) |
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+</glep> |
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|
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</gleps> |
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|
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|
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|
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1.1 xml/htdocs/proj/en/glep/glep-0055.html |
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|
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file : http://sources.gentoo.org/viewcvs.py/gentoo/xml/htdocs/proj/en/glep/glep-0055.html?rev=1.1&view=markup |
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plain: http://sources.gentoo.org/viewcvs.py/gentoo/xml/htdocs/proj/en/glep/glep-0055.html?rev=1.1&content-type=text/plain |
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|
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Index: glep-0055.html |
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=================================================================== |
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<?xml version="1.0" encoding="utf-8" ?> |
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> |
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<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> |
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<!-- |
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This HTML is auto-generated. DO NOT EDIT THIS FILE! If you are writing a new |
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PEP, see http://www.python.org/peps/pep-0001.html for instructions and links |
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to templates. DO NOT USE THIS HTML FILE AS YOUR TEMPLATE! |
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--> |
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<head> |
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> |
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<meta name="generator" content="Docutils 0.4: http://docutils.sourceforge.net/" /> |
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<title>GLEP 55 -- Use EAPI-suffixed ebuilds (.ebuild-EAPI)</title> |
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<link rel="stylesheet" href="tools/glep.css" type="text/css" /> |
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</head> |
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<body bgcolor="white"> |
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<table class="navigation" cellpadding="0" cellspacing="0" |
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width="100%" border="0"> |
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<tr><td class="navicon" width="150" height="35"> |
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<a href="http://www.gentoo.org/" title="Gentoo Linux Home Page"> |
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<img src="http://www.gentoo.org/images/gentoo-new.gif" alt="[Gentoo]" |
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border="0" width="150" height="35" /></a></td> |
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<td class="textlinks" align="left"> |
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[<b><a href="http://www.gentoo.org/">Gentoo Linux Home</a></b>] |
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[<b><a href="http://www.gentoo.org/peps">GLEP Index</a></b>] |
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[<b><a href="http://www.gentoo.org/proj/en/glep/glep-0055.txt">GLEP Source</a></b>] |
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</td></tr></table> |
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<table class="rfc2822 docutils field-list" frame="void" rules="none"> |
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<col class="field-name" /> |
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<col class="field-body" /> |
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<tbody valign="top"> |
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<tr class="field"><th class="field-name">GLEP:</th><td class="field-body">55</td> |
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</tr> |
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<tr class="field"><th class="field-name">Title:</th><td class="field-body">Use EAPI-suffixed ebuilds (.ebuild-EAPI)</td> |
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</tr> |
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<tr class="field"><th class="field-name">Version:</th><td class="field-body">1.1</td> |
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</tr> |
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<tr class="field"><th class="field-name">Last-Modified:</th><td class="field-body"><a class="reference" href="http://www.gentoo.org/cgi-bin/viewcvs.cgi/xml/htdocs/proj/en/glep/glep-0055.txt?cvsroot=gentoo">2008/01/05 02:36:35</a></td> |
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</tr> |
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<tr class="field"><th class="field-name">Author:</th><td class="field-body">Piotr Jaroszyński <peper at gentoo.org></td> |
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</tr> |
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<tr class="field"><th class="field-name">Status:</th><td class="field-body">Draft</td> |
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</tr> |
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<tr class="field"><th class="field-name">Type:</th><td class="field-body">Standards Track</td> |
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</tr> |
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<tr class="field"><th class="field-name">Content-Type:</th><td class="field-body"><a class="reference" href="glep-0002.html">text/x-rst</a></td> |
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</tr> |
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<tr class="field"><th class="field-name">Created:</th><td class="field-body">17-Dec-2007</td> |
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</tr> |
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<tr class="field"><th class="field-name">Post-History:</th><td class="field-body">17-Dec-2007, 22-Dec-2007</td> |
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</tr> |
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</tbody> |
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</table> |
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<hr /> |
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<div class="contents topic"> |
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<p class="topic-title first"><a id="contents" name="contents">Contents</a></p> |
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<ul class="simple"> |
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<li><a class="reference" href="#abstract" id="id3" name="id3">Abstract</a></li> |
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<li><a class="reference" href="#problem" id="id4" name="id4">Problem</a></li> |
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<li><a class="reference" href="#abstract-solution" id="id5" name="id5">Abstract solution</a></li> |
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<li><a class="reference" href="#proposed-solution" id="id6" name="id6">Proposed solution</a></li> |
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<li><a class="reference" href="#specification" id="id7" name="id7">Specification</a></li> |
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<li><a class="reference" href="#application" id="id8" name="id8">Application</a></li> |
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<li><a class="reference" href="#other-ideas" id="id9" name="id9">Other ideas</a></li> |
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<li><a class="reference" href="#references" id="id10" name="id10">References</a></li> |
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<li><a class="reference" href="#copyright" id="id11" name="id11">Copyright</a></li> |
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</ul> |
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</div> |
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<blockquote> |
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<p>"A little learning is a dangerous thing; drink deep, or taste not the Pierian |
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spring: there shallow draughts intoxicate the brain, and drinking largely |
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sobers us again."</p> |
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<p class="attribution">—Alexander Pope, An Essay on Criticism</p> |
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</blockquote> |
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<div class="section"> |
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<h1><a class="toc-backref" href="#id3" id="abstract" name="abstract">Abstract</a></h1> |
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<p>This GLEP proposes usage of EAPI-suffixed file extensions for ebuilds (for |
| 125 |
example, foo-1.2.3.ebuild-1).</p> |
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</div> |
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<div class="section"> |
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<h1><a class="toc-backref" href="#id4" id="problem" name="problem">Problem</a></h1> |
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<p>The current way of specifying the EAPI in ebuilds is flawed. In order to get the |
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EAPI the package manager needs to source the ebuild, which itself needs the EAPI |
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in the first place. Otherwise it imposes a serious limitation, namely every ebuild, |
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using any of the future EAPIs, will have to be source'able by old package |
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managers and hence there is no way to:</p> |
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<blockquote> |
| 135 |
<ul class="simple"> |
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<li>Change behaviour of inherit in any way (for example, to extend or change |
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eclass functionality).</li> |
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<li>Add new global scope functions in any sane way.</li> |
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<li>Extend versioning rules in an EAPI - for example, addition of the scm |
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suffix - GLEP54 <a class="footnote-reference" href="#glep54" id="id1" name="id1">[1]</a>.</li> |
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</ul> |
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</blockquote> |
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</div> |
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<div class="section"> |
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<h1><a class="toc-backref" href="#id5" id="abstract-solution" name="abstract-solution">Abstract solution</a></h1> |
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<p>A solution to this problem has to lift those limitations and the only way to do |
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it is to make the EAPI of an ebuild available to the package managers in a way |
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that doesn't require them to source the ebuild. Another important requirement is |
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for the solution to be backward compatible, which has the pleasant side-effect |
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of making the solution applicable in the Gentoo tree right away. Opposed to |
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waiting an arbitrary amount of time, which is never long enough anyway, as the |
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issues listed on the common portage problems page - <a class="footnote-reference" href="#portageproblems" id="id2" name="id2">[2]</a> - show.</p> |
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</div> |
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<div class="section"> |
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<h1><a class="toc-backref" href="#id6" id="proposed-solution" name="proposed-solution">Proposed solution</a></h1> |
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<p>The proposed solution is to use EAPI-suffixed file extensions for ebuilds. This |
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allows package managers to trivially read the EAPI from the ebuild filename. It |
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is also backward compatible, because currently ebuilds are recognised by the |
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<tt class="docutils literal"><span class="pre">.ebuild</span></tt> file extension and hence EAPI-suffixed ebuilds are simply ignored by |
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the package managers.</p> |
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</div> |
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<div class="section"> |
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<h1><a class="toc-backref" href="#id7" id="specification" name="specification">Specification</a></h1> |
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<p>Ebuild filename extension syntax: <tt class="docutils literal"><span class="pre">ebuild[-<EAPI>]</span></tt>, where <tt class="docutils literal"><span class="pre">[]</span></tt> denotes an |
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optional part, and <tt class="docutils literal"><span class="pre"><EAPI></span></tt> is the EAPI of the ebuild.</p> |
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<p>Let's call the EAPI included in the ebuild filename the pre-source EAPI, and the |
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EAPI set inside the ebuild the post-source EAPI. Given these two, the final EAPI |
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used by the ebuild can be established by following these steps:</p> |
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<blockquote> |
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<ul class="simple"> |
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<li>If the pre-source EAPI is not set it defaults to 0.</li> |
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<li>If the pre-source EAPI is not recognised it is returned immediately.</li> |
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<li>If the post-source EAPI is not set, it defaults to the pre-source EAPI.</li> |
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<li>post-source EAPI is returned.</li> |
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</ul> |
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</blockquote> |
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<p>The above process should be only used to generate the metadata cache. Should the |
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pre-source EAPI be unsupported the cache entry cannot be generated.</p> |
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<p>Ebuilds with unsupported EAPIs are masked.</p> |
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<p>QA tools should consider it an error for both EAPIs to be set explicitly to |
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different values. Package managers may warn, but must use the post-source EAPI |
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in such cases.</p> |
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<p>Examples:</p> |
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<blockquote> |
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<ul> |
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<li><dl class="first docutils"> |
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<dt><tt class="docutils literal"><span class="pre">pkg-1.ebuild</span></tt>, no EAPI set inside the ebuild</dt> |
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<dd><p class="first last">pre-source EAPI defaults 0, post-source EAPI defaults to pre-source EAPI. |
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EAPI 0 is used.</p> |
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</dd> |
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</dl> |
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</li> |
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<li><dl class="first docutils"> |
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<dt><tt class="docutils literal"><span class="pre">pkg-2.ebuild-1</span></tt>, no EAPI set inside the ebuild</dt> |
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<dd><p class="first last">pre-source EAPI is 1, post-source EAPI defaults to pre-source EAPI. |
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EAPI 1 is used.</p> |
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</dd> |
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</dl> |
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</li> |
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<li><dl class="first docutils"> |
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<dt><tt class="docutils literal"><span class="pre">pkg-3.ebuild</span></tt>, <tt class="docutils literal"><span class="pre">EAPI="1"</span></tt></dt> |
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<dd><p class="first last">pre-source EAPI defaults to 0, post-source EAPI is 1. |
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EAPI 1 is used.</p> |
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</dd> |
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</dl> |
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</li> |
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<li><dl class="first docutils"> |
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<dt><tt class="docutils literal"><span class="pre">pkg-4.ebuild-2</span></tt>, <tt class="docutils literal"><span class="pre">EAPI="1"</span></tt></dt> |
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<dd><p class="first last">pre-source EAPI is 2, post-source EAPI is 1. |
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EAPI 1 is used, but note that one should <strong>never</strong> explicitly set both |
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EAPIs to different values.</p> |
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</dd> |
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</dl> |
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</li> |
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<li><dl class="first docutils"> |
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<dt><tt class="docutils literal"><span class="pre">pkg-5.ebuild-2</span></tt>, no EAPI set inside the ebuild, package manager not supporting EAPI 2</dt> |
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<dd><p class="first last">pre-source EAPI is 2, post-source EAPI is never checked. |
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ebuild masked because of the unsupported pre-source EAPI.</p> |
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</dd> |
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</dl> |
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</li> |
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<li><dl class="first docutils"> |
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<dt><tt class="docutils literal"><span class="pre">pkg-6.ebuild</span></tt>, <tt class="docutils literal"><span class="pre">EAPI="2"</span></tt>, package manager not supporting EAPI 2</dt> |
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<dd><p class="first last">pre-source EAPI defaults to 0, post-source EAPI is 2 (assuming the |
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package manager didn't die when sourcing the ebuild thinking that EAPI 0 |
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is used). |
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ebuild masked because of the unsupported post-source EAPI.</p> |
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</dd> |
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</dl> |
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</li> |
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</ul> |
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</blockquote> |
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<p>Note that it is still not permitted to have more than one ebuild with equal |
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category, package name, and version. Although it would have the advantage of |
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allowing to provide backward compatible ebuilds, it would introduce problems |
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too. The first is the requirement to have strict EAPI ordering, the second is |
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ensuring that all the ebuilds for a single category/package-version are |
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equivalent, i.e. installing any of them has exactly the same effect to the |
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system.</p> |
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</div> |
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<div class="section"> |
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<h1><a class="toc-backref" href="#id8" id="application" name="application">Application</a></h1> |
| 243 |
<p>Note that the developers should only set the pre-source EAPI. The process |
| 244 |
described above is only necessary to avoid undefined behaviour in corner cases |
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and to retain backwards compatibility.</p> |
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<p>QA tools may warn if the post-source EAPI is set at all, thus helping with the |
| 247 |
transition to the new format.</p> |
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</div> |
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<div class="section"> |
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<h1><a class="toc-backref" href="#id9" id="other-ideas" name="other-ideas">Other ideas</a></h1> |
| 251 |
<p>There were some other solutions proposed on the mailing list:</p> |
| 252 |
<blockquote> |
| 253 |
<ul> |
| 254 |
<li><dl class="first docutils"> |
| 255 |
<dt>Set the EAPI inside the ebuild in a way that makes it easy to fetch it</dt> |
| 256 |
<dd><ul class="first last simple"> |
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<li>Doesn't meet the backward compatibility requirement.</li> |
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<li>Isn't forward compatible either.</li> |
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<li>Could be confusing as ebuilds, and not without a reason, are |
| 260 |
considered bash scripts and this would impose additional restrictions.</li> |
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</ul> |
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</dd> |
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</dl> |
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</li> |
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<li><dl class="first docutils"> |
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<dt>Do the above and change the ebuild extension to <tt class="docutils literal"><span class="pre">.ebuild-ng</span></tt></dt> |
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<dd><ul class="first last simple"> |
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<li>Meets the backward compatibility requirement.</li> |
| 269 |
<li>Still can be confusing.</li> |
| 270 |
<li>Isn't really forward compatible. What would be after <tt class="docutils literal"><span class="pre">.ebuild-ng</span></tt>? |
| 271 |
<tt class="docutils literal"><span class="pre">.ebuild-ng-ng</span></tt>?</li> |
| 272 |
</ul> |
| 273 |
</dd> |
| 274 |
</dl> |
| 275 |
</li> |
| 276 |
<li><dl class="first docutils"> |
| 277 |
<dt>Use different subdirectories for different EAPIs, i.e. cat/pkg/eapiX/</dt> |
| 278 |
<dd><ul class="first last simple"> |
| 279 |
<li>Meets both requirements.</li> |
| 280 |
<li>Introduces a noticeable performance hit (several more directory reads |
| 281 |
in an I/O bound operation).</li> |
| 282 |
<li>Makes it much harder for maintainers to see what they have.</li> |
| 283 |
</ul> |
| 284 |
</dd> |
| 285 |
</dl> |
| 286 |
</li> |
| 287 |
</ul> |
| 288 |
</blockquote> |
| 289 |
</div> |
| 290 |
<div class="section"> |
| 291 |
<h1><a class="toc-backref" href="#id10" id="references" name="references">References</a></h1> |
| 292 |
<table class="docutils footnote" frame="void" id="glep54" rules="none"> |
| 293 |
<colgroup><col class="label" /><col /></colgroup> |
| 294 |
<tbody valign="top"> |
| 295 |
<tr><td class="label"><a class="fn-backref" href="#id1" name="glep54">[1]</a></td><td>GLEP 54, scm package version suffix |
| 296 |
(<a class="reference" href="http://glep.gentoo.org/glep-0054.html">http://glep.gentoo.org/glep-0054.html</a>)</td></tr> |
| 297 |
</tbody> |
| 298 |
</table> |
| 299 |
<table class="docutils footnote" frame="void" id="portageproblems" rules="none"> |
| 300 |
<colgroup><col class="label" /><col /></colgroup> |
| 301 |
<tbody valign="top"> |
| 302 |
<tr><td class="label"><a class="fn-backref" href="#id2" name="portageproblems">[2]</a></td><td>Common portage problems |
| 303 |
(<a class="reference" href="http://www.gentoo.org/proj/en/portage/doc/common-problems.xml">http://www.gentoo.org/proj/en/portage/doc/common-problems.xml</a>)</td></tr> |
| 304 |
</tbody> |
| 305 |
</table> |
| 306 |
</div> |
| 307 |
<div class="section"> |
| 308 |
<h1><a class="toc-backref" href="#id11" id="copyright" name="copyright">Copyright</a></h1> |
| 309 |
<p>This document has been placed in the public domain.</p> |
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<!-- vim: set tw=80 fileencoding=utf-8 spell spelllang=en et : --> |
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</div> |
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</div> |
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<div class="footer"> |
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<hr class="footer" /> |
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<a class="reference" href="glep-0055.txt">View document source</a>. |
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Generated on: 2008-01-05 02:38 UTC. |
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Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source. |
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</div> |
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</body> |
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</html> |
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-- |
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