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8 g2boojum 1.1 <title>GLEP 21 -- User-defined Package Sets</title>
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21 g2boojum 1.1 [<b><a href="http://www.gentoo.org/proj/en/glep/glep-0021.txt">GLEP Source</a></b>]
22     </td></tr></table>
23 g2boojum 1.3 <table class="rfc2822 docutils field-list" frame="void" rules="none">
24 g2boojum 1.1 <col class="field-name" />
25     <col class="field-body" />
26     <tbody valign="top">
27     <tr class="field"><th class="field-name">GLEP:</th><td class="field-body">21</td>
28     </tr>
29     <tr class="field"><th class="field-name">Title:</th><td class="field-body">User-defined Package Sets</td>
30     </tr>
31 antarus 1.7 <tr class="field"><th class="field-name">Version:</th><td class="field-body">1.4</td>
32 g2boojum 1.1 </tr>
33 antarus 1.7 <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-0021.txt?cvsroot=gentoo">2007/04/21 03:13:16</a></td>
34 g2boojum 1.1 </tr>
35 g2boojum 1.3 <tr class="field"><th class="field-name">Author:</th><td class="field-body">Tal Peer &lt;coredumb&#32;&#97;t&#32;gentoo.org&gt;,
36     Alec Warner &lt;antarus&#32;&#97;t&#32;gentoo.org&gt;</td>
37 g2boojum 1.1 </tr>
38 antarus 1.6 <tr class="field"><th class="field-name">Status:</th><td class="field-body">Deferred</td>
39 g2boojum 1.1 </tr>
40     <tr class="field"><th class="field-name">Type:</th><td class="field-body">Standards Track</td>
41     </tr>
42     <tr class="field"><th class="field-name">Discussed-To:</th><td class="field-body"><a class="reference" href="mailto:gentoo-portage-dev&#64;lists.gentoo.org">gentoo-portage-dev&#64;lists.gentoo.org</a></td>
43     </tr>
44     <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>
45     </tr>
46     <tr class="field"><th class="field-name">Created:</th><td class="field-body">22-Feb-2004</td>
47     </tr>
48 g2boojum 1.3 <tr class="field"><th class="field-name">Post-History:</th><td class="field-body">6-Mar-2004, 3-Sep-2006</td>
49 g2boojum 1.1 </tr>
50     </tbody>
51     </table>
52     <hr />
53 g2boojum 1.3 <div class="contents topic">
54     <p class="topic-title first"><a id="contents" name="contents">Contents</a></p>
55 g2boojum 1.1 <ul class="simple">
56 g2boojum 1.3 <li><a class="reference" href="#status" id="id3" name="id3">Status</a></li>
57     <li><a class="reference" href="#abstract" id="id4" name="id4">Abstract</a></li>
58     <li><a class="reference" href="#motivation" id="id5" name="id5">Motivation</a></li>
59     <li><a class="reference" href="#specification" id="id6" name="id6">Specification</a><ul>
60     <li><a class="reference" href="#using-user-defined-sets-with-emerge" id="id7" name="id7">Using User-defined Sets With Emerge</a></li>
61     <li><a class="reference" href="#compatibility-with-other-portage-features" id="id8" name="id8">Compatibility With Other Portage Features</a></li>
62 g2boojum 1.1 </ul>
63     </li>
64 g2boojum 1.3 <li><a class="reference" href="#implementation" id="id9" name="id9">Implementation</a></li>
65     <li><a class="reference" href="#rationale" id="id10" name="id10">Rationale</a></li>
66     <li><a class="reference" href="#backwards-compatibility" id="id11" name="id11">Backwards Compatibility</a></li>
67     <li><a class="reference" href="#references" id="id12" name="id12">References</a></li>
68     <li><a class="reference" href="#copyright" id="id13" name="id13">Copyright</a></li>
69 g2boojum 1.1 </ul>
70     </div>
71 g2boojum 1.3 <div class="section">
72     <h1><a class="toc-backref" href="#id3" id="status" name="status">Status</a></h1>
73     <p>Taken over by antarus.</p>
74     </div>
75     <div class="section">
76     <h1><a class="toc-backref" href="#id4" id="abstract" name="abstract">Abstract</a></h1>
77 g2boojum 1.1 <p>In Portage, package sets (formerly known as 'classes' or 'targets')
78     are mere groups of packages, grouped together to allow easier updating
79     and handling of them. Currently it is impossible to define sets further
80     than the two default ones: &quot;system&quot; and &quot;world&quot;.</p>
81     </div>
82 g2boojum 1.3 <div class="section">
83     <h1><a class="toc-backref" href="#id5" id="motivation" name="motivation">Motivation</a></h1>
84 g2boojum 1.1 <p>Over the months, quite a few requests for user-defined sets were
85     made by users and developers, either by posting bugs, messages to
86     mailing lists or on IRC. Usually the response is that this is an
87     awesome idea, but no one ever took the time to actually define it
88     properly and implement it.</p>
89     <p>This document offers a specification for the implementation of
90     user-defined sets using configuration files similar to the current
91     world/system sets use.</p>
92     </div>
93 g2boojum 1.3 <div class="section">
94     <h1><a class="toc-backref" href="#id6" id="specification" name="specification">Specification</a></h1>
95 g2boojum 1.1 <p>The proposed implementation uses a one file per set approach, meaning
96     each package set is defined in a single file. All set definition files
97 g2boojum 1.3 will reside in a directory <tt class="docutils literal"><span class="pre">/etc/portage/sets/</span></tt> and each set's name
98 g2boojum 1.1 will be its file name. Therefore, if one defines a set in
99     /etc/portage/sets/foo-set, the set name will be 'foo-set'. Usual
100     package naming rules <a class="footnote-reference" href="#name-rules" id="id1" name="id1">[1]</a> also apply to sets.</p>
101     <p>As it is impossible to create two or more files with identical names
102     in the same directory, a theoretic conflict between two different sets
103     sharing the same name is impossible. However, users may define a
104     package set whose name conflicts with one more or packages (for ambiguity
105     resolution, see below).</p>
106     <p>Syntax for the package list file is the same as the world file syntax,
107     as described in the Portage manpage <a class="footnote-reference" href="#portage-manpage" id="id2" name="id2">[2]</a>, with one
108     addition: sets may not be 'inherited' by other sets, only packages may
109     be listed. There is no limitation to the number of packages in a set
110     or to the number of sets a package may belong to.</p>
111 g2boojum 1.3 <div class="section">
112     <h2><a class="toc-backref" href="#id7" id="using-user-defined-sets-with-emerge" name="using-user-defined-sets-with-emerge">Using User-defined Sets With Emerge</a></h2>
113 g2boojum 1.1 <p>The user-defined sets will be available either directly or using
114     the --package-set option, As in:</p>
115     <pre class="literal-block">
116     # Basically the same:
117     emerge foo-set
118     emerge --package-set foo-set
119     </pre>
120     <p>The --package-set option is introduced to bypass ambiguities, as
121     illustrated in the next example:</p>
122     <pre class="literal-block">
123     emerge foo # Where foo is both a set and a one or more
124     # existing packages. This will cause emerge to show
125     # the ambiguity, ask us to be more
126     # specific, and stop.
128     emerge --package-set foo # So we specify that what we actually
129     # meant was the package set.
131     emerge cat-bar/foo # Or we specify the exact package name.
132     </pre>
133     <p>When running emerge with the --pretend option, sets will be
134     expanded to the packages they are comprised off in the output, as with
135     the current system-defined sets.</p>
136     <p>Only one set may be passed to portage at time, and sets can not
137     be mixed with ordinary packages. Thus, the following snippets are
138 g2boojum 1.3 all invalid and will result in an error (assuming <tt class="docutils literal"><span class="pre">foo-set</span></tt> and
139     <tt class="docutils literal"><span class="pre">bar-set</span></tt> are defined as sets):</p>
140 g2boojum 1.1 <pre class="literal-block">
141     emerge foo-set glibc
142     emerge bar-set system
143     emerge world foo-set gcc
144     </pre>
145     </div>
146 g2boojum 1.3 <div class="section">
147     <h2><a class="toc-backref" href="#id8" id="compatibility-with-other-portage-features" name="compatibility-with-other-portage-features">Compatibility With Other Portage Features</a></h2>
148 g2boojum 1.1 <ul class="simple">
149     <li>Dependencies:
150     Package sets (both system-defined and user-defined) may not be
151     depended on by ordinary packages and eclasses.</li>
152     <li>package.mask:
153 g2boojum 1.3 Masking a package set through the <tt class="docutils literal"><span class="pre">package.mask</span></tt> file is forbidden.
154 g2boojum 1.2 In order to 'mask' a package set, one should move it away from the
155     sets directory.</li>
156 g2boojum 1.1 <li>package.use:
157 g2boojum 1.3 USE flags may not be defined for sets in the <tt class="docutils literal"><span class="pre">package.use</span></tt> file.</li>
158 g2boojum 1.1 </ul>
159     </div>
160     </div>
161 g2boojum 1.3 <div class="section">
162     <h1><a class="toc-backref" href="#id9" id="implementation" name="implementation">Implementation</a></h1>
163 g2boojum 1.1 <p>The implementation of the package sets concept in Portage should be
164     mostly done in portage.py, and only the interface parts should be
165     added to emerge itself, to keep the separation between interface and
166     logic.</p>
167     <p>The amount of work needed for implementation is not trivial, but not
168     huge either.</p>
169     </div>
170 g2boojum 1.3 <div class="section">
171     <h1><a class="toc-backref" href="#id10" id="rationale" name="rationale">Rationale</a></h1>
172 g2boojum 1.1 <p>The one file per set approach makes it easy to list the sets which are
173 g2boojum 1.3 defined on a system by just listing the <tt class="docutils literal"><span class="pre">/etc/portage/sets</span></tt>
174 g2boojum 1.1 directory contents. Additionally, it makes the set lookup process more
175     efficient as it only requires to check if a file exists.</p>
176     <p>I chose the --package-set option over the --set option for explicitly
177     telling portage to emerge a set mostly because --set implies setting
178     an environment variable, or such.</p>
179 g2boojum 1.3 <p>Allowing sets' USE flags to be manipulated through the <tt class="docutils literal"><span class="pre">package.use</span></tt>
180 g2boojum 1.1 file would have done more harm than good, for several reasons:</p>
181     <ul class="simple">
182     <li>If a USE flag is turned on (i.e. 'foo') for a set and the same USE
183     flag is turned off (i.e. '-foo'), for a package which is part of
184     the set, it is unclear which setting should take precedence.</li>
185     <li>Similarly, if a USE flag is turned on for a set and the same USE flag
186     is turned off for a set that is a subset of the original set, it is
187     unclear which setting should take precedence.</li>
188     <li>If a USE flag is defined (either off or on) for a set and a package
189     that belongs in the set is to be emerged, it is unclear whether the
190     USE flag should be defined when emerging the package in question.</li>
191     </ul>
192     <p>Therefore, I have decided it would be better to disallow setting USE
193     flags for sets.</p>
194     </div>
195 g2boojum 1.3 <div class="section">
196     <h1><a class="toc-backref" href="#id11" id="backwards-compatibility" name="backwards-compatibility">Backwards Compatibility</a></h1>
197 g2boojum 1.1 <p>Backwards compatibility with the current situation, in which only two
198     system-defined sets exist can be kept in one of two ways:</p>
199     <ol class="arabic simple">
200     <li>Leaving the situation as is - the 'world' and 'system' sets are
201     hard-coded in Portage.</li>
202     <li>Distributing default 'system' and 'world' files under the
203 g2boojum 1.3 <tt class="docutils literal"><span class="pre">/etc/portage/sets/</span></tt> directory.</li>
204 g2boojum 1.1 </ol>
205     <p>Other than that, there are no other backwards compatibility concerns
206     involved.</p>
207     </div>
208 g2boojum 1.3 <div class="section">
209     <h1><a class="toc-backref" href="#id12" id="references" name="references">References</a></h1>
210     <table class="docutils footnote" frame="void" id="name-rules" rules="none">
211 g2boojum 1.1 <colgroup><col class="label" /><col /></colgroup>
212     <tbody valign="top">
213     <tr><td class="label"><a class="fn-backref" href="#id1" name="name-rules">[1]</a></td><td>Gentoo Linux Development Policy - Ebuild Policy
214     (<a class="reference" href="http://www.gentoo.org/doc/en/policy.xml#doc_chap3">http://www.gentoo.org/doc/en/policy.xml#doc_chap3</a>)</td></tr>
215     </tbody>
216     </table>
217 g2boojum 1.3 <table class="docutils footnote" frame="void" id="portage-manpage" rules="none">
218 g2boojum 1.1 <colgroup><col class="label" /><col /></colgroup>
219     <tbody valign="top">
220     <tr><td class="label"><a class="fn-backref" href="#id2" name="portage-manpage">[2]</a></td><td><a class="reference" href="http://www.gentoo.org/cgi-bin/viewcvs.cgi/portage/man/portage.5?root=gentoo-src">http://www.gentoo.org/cgi-bin/viewcvs.cgi/portage/man/portage.5?root=gentoo-src</a></td></tr>
221     </tbody>
222     </table>
223     </div>
224 g2boojum 1.3 <div class="section">
225     <h1><a class="toc-backref" href="#id13" id="copyright" name="copyright">Copyright</a></h1>
226 g2boojum 1.1 <p>This document has been placed in the public domain.</p>
227     </div>
228 g2boojum 1.3
229 g2boojum 1.1 </div>
230     <div class="footer">
231 g2boojum 1.3 <hr class="footer" />
232 g2boojum 1.1 <a class="reference" href="glep-0021.txt">View document source</a>.
233 antarus 1.7 Generated on: 2007-10-13 13:39 UTC.
234 g2boojum 1.1 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.
235 g2boojum 1.3
236 g2boojum 1.1 </div>
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