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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 1.9 <tr class="field"><th class="field-name">Version:</th><td class="field-body">1.6</td>
32 g2boojum 1.1 </tr>
33 antarus 1.9 <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">2009/02/20 09:19:56</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 1.9 <tr class="field"><th class="field-name">Status:</th><td class="field-body">Final</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 genone 1.8 <p>Abandoned. Package set support has been added in portage-2.2, but it
74     doesn't match the description in this document in many cases, and the
75     document has several major gaps regarding the behavior and restrictions
76     of package sets.</p>
77 g2boojum 1.3 </div>
78     <div class="section">
79     <h1><a class="toc-backref" href="#id4" id="abstract" name="abstract">Abstract</a></h1>
80 g2boojum 1.1 <p>In Portage, package sets (formerly known as 'classes' or 'targets')
81     are mere groups of packages, grouped together to allow easier updating
82     and handling of them. Currently it is impossible to define sets further
83     than the two default ones: &quot;system&quot; and &quot;world&quot;.</p>
84     </div>
85 g2boojum 1.3 <div class="section">
86     <h1><a class="toc-backref" href="#id5" id="motivation" name="motivation">Motivation</a></h1>
87 g2boojum 1.1 <p>Over the months, quite a few requests for user-defined sets were
88     made by users and developers, either by posting bugs, messages to
89     mailing lists or on IRC. Usually the response is that this is an
90     awesome idea, but no one ever took the time to actually define it
91     properly and implement it.</p>
92     <p>This document offers a specification for the implementation of
93     user-defined sets using configuration files similar to the current
94     world/system sets use.</p>
95     </div>
96 g2boojum 1.3 <div class="section">
97     <h1><a class="toc-backref" href="#id6" id="specification" name="specification">Specification</a></h1>
98 g2boojum 1.1 <p>The proposed implementation uses a one file per set approach, meaning
99     each package set is defined in a single file. All set definition files
100 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
101 g2boojum 1.1 will be its file name. Therefore, if one defines a set in
102     /etc/portage/sets/foo-set, the set name will be 'foo-set'. Usual
103     package naming rules <a class="footnote-reference" href="#name-rules" id="id1" name="id1">[1]</a> also apply to sets.</p>
104     <p>As it is impossible to create two or more files with identical names
105     in the same directory, a theoretic conflict between two different sets
106     sharing the same name is impossible. However, users may define a
107     package set whose name conflicts with one more or packages (for ambiguity
108     resolution, see below).</p>
109     <p>Syntax for the package list file is the same as the world file syntax,
110     as described in the Portage manpage <a class="footnote-reference" href="#portage-manpage" id="id2" name="id2">[2]</a>, with one
111     addition: sets may not be 'inherited' by other sets, only packages may
112     be listed. There is no limitation to the number of packages in a set
113     or to the number of sets a package may belong to.</p>
114 g2boojum 1.3 <div class="section">
115     <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>
116 g2boojum 1.1 <p>The user-defined sets will be available either directly or using
117     the --package-set option, As in:</p>
118     <pre class="literal-block">
119     # Basically the same:
120     emerge foo-set
121     emerge --package-set foo-set
122     </pre>
123     <p>The --package-set option is introduced to bypass ambiguities, as
124     illustrated in the next example:</p>
125     <pre class="literal-block">
126     emerge foo # Where foo is both a set and a one or more
127     # existing packages. This will cause emerge to show
128     # the ambiguity, ask us to be more
129     # specific, and stop.
130    
131     emerge --package-set foo # So we specify that what we actually
132     # meant was the package set.
133    
134     emerge cat-bar/foo # Or we specify the exact package name.
135     </pre>
136     <p>When running emerge with the --pretend option, sets will be
137     expanded to the packages they are comprised off in the output, as with
138     the current system-defined sets.</p>
139     <p>Only one set may be passed to portage at time, and sets can not
140     be mixed with ordinary packages. Thus, the following snippets are
141 g2boojum 1.3 all invalid and will result in an error (assuming <tt class="docutils literal"><span class="pre">foo-set</span></tt> and
142     <tt class="docutils literal"><span class="pre">bar-set</span></tt> are defined as sets):</p>
143 g2boojum 1.1 <pre class="literal-block">
144     emerge foo-set glibc
145     emerge bar-set system
146     emerge world foo-set gcc
147     </pre>
148     </div>
149 g2boojum 1.3 <div class="section">
150     <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>
151 g2boojum 1.1 <ul class="simple">
152     <li>Dependencies:
153     Package sets (both system-defined and user-defined) may not be
154     depended on by ordinary packages and eclasses.</li>
155     <li>package.mask:
156 g2boojum 1.3 Masking a package set through the <tt class="docutils literal"><span class="pre">package.mask</span></tt> file is forbidden.
157 g2boojum 1.2 In order to 'mask' a package set, one should move it away from the
158     sets directory.</li>
159 g2boojum 1.1 <li>package.use:
160 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>
161 g2boojum 1.1 </ul>
162     </div>
163     </div>
164 g2boojum 1.3 <div class="section">
165     <h1><a class="toc-backref" href="#id9" id="implementation" name="implementation">Implementation</a></h1>
166 g2boojum 1.1 <p>The implementation of the package sets concept in Portage should be
167     mostly done in portage.py, and only the interface parts should be
168     added to emerge itself, to keep the separation between interface and
169     logic.</p>
170     <p>The amount of work needed for implementation is not trivial, but not
171     huge either.</p>
172     </div>
173 g2boojum 1.3 <div class="section">
174     <h1><a class="toc-backref" href="#id10" id="rationale" name="rationale">Rationale</a></h1>
175 g2boojum 1.1 <p>The one file per set approach makes it easy to list the sets which are
176 g2boojum 1.3 defined on a system by just listing the <tt class="docutils literal"><span class="pre">/etc/portage/sets</span></tt>
177 g2boojum 1.1 directory contents. Additionally, it makes the set lookup process more
178     efficient as it only requires to check if a file exists.</p>
179     <p>I chose the --package-set option over the --set option for explicitly
180     telling portage to emerge a set mostly because --set implies setting
181     an environment variable, or such.</p>
182 g2boojum 1.3 <p>Allowing sets' USE flags to be manipulated through the <tt class="docutils literal"><span class="pre">package.use</span></tt>
183 g2boojum 1.1 file would have done more harm than good, for several reasons:</p>
184     <ul class="simple">
185     <li>If a USE flag is turned on (i.e. 'foo') for a set and the same USE
186     flag is turned off (i.e. '-foo'), for a package which is part of
187     the set, it is unclear which setting should take precedence.</li>
188     <li>Similarly, if a USE flag is turned on for a set and the same USE flag
189     is turned off for a set that is a subset of the original set, it is
190     unclear which setting should take precedence.</li>
191     <li>If a USE flag is defined (either off or on) for a set and a package
192     that belongs in the set is to be emerged, it is unclear whether the
193     USE flag should be defined when emerging the package in question.</li>
194     </ul>
195     <p>Therefore, I have decided it would be better to disallow setting USE
196     flags for sets.</p>
197     </div>
198 g2boojum 1.3 <div class="section">
199     <h1><a class="toc-backref" href="#id11" id="backwards-compatibility" name="backwards-compatibility">Backwards Compatibility</a></h1>
200 g2boojum 1.1 <p>Backwards compatibility with the current situation, in which only two
201     system-defined sets exist can be kept in one of two ways:</p>
202     <ol class="arabic simple">
203     <li>Leaving the situation as is - the 'world' and 'system' sets are
204     hard-coded in Portage.</li>
205     <li>Distributing default 'system' and 'world' files under the
206 g2boojum 1.3 <tt class="docutils literal"><span class="pre">/etc/portage/sets/</span></tt> directory.</li>
207 g2boojum 1.1 </ol>
208     <p>Other than that, there are no other backwards compatibility concerns
209     involved.</p>
210     </div>
211 g2boojum 1.3 <div class="section">
212     <h1><a class="toc-backref" href="#id12" id="references" name="references">References</a></h1>
213     <table class="docutils footnote" frame="void" id="name-rules" rules="none">
214 g2boojum 1.1 <colgroup><col class="label" /><col /></colgroup>
215     <tbody valign="top">
216     <tr><td class="label"><a class="fn-backref" href="#id1" name="name-rules">[1]</a></td><td>Gentoo Linux Development Policy - Ebuild Policy
217     (<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>
218     </tbody>
219     </table>
220 g2boojum 1.3 <table class="docutils footnote" frame="void" id="portage-manpage" rules="none">
221 g2boojum 1.1 <colgroup><col class="label" /><col /></colgroup>
222     <tbody valign="top">
223     <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>
224     </tbody>
225     </table>
226     </div>
227 g2boojum 1.3 <div class="section">
228     <h1><a class="toc-backref" href="#id13" id="copyright" name="copyright">Copyright</a></h1>
229 g2boojum 1.1 <p>This document has been placed in the public domain.</p>
230     </div>
231 g2boojum 1.3
232 g2boojum 1.1 </div>
233     <div class="footer">
234 g2boojum 1.3 <hr class="footer" />
235 g2boojum 1.1 <a class="reference" href="glep-0021.txt">View document source</a>.
236 antarus 1.9 Generated on: 2009-02-20 09:21 UTC.
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238 g2boojum 1.3
239 g2boojum 1.1 </div>
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