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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 <tr class="field"><th class="field-name">Version:</th><td class="field-body">1.6</td>
32 </tr>
33 <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 </tr>
35 <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 </tr>
38 <tr class="field"><th class="field-name">Status:</th><td class="field-body">Final</td>
39 </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 <tr class="field"><th class="field-name">Post-History:</th><td class="field-body">6-Mar-2004, 3-Sep-2006</td>
49 </tr>
50 </tbody>
51 </table>
52 <hr />
53 <div class="contents topic">
54 <p class="topic-title first"><a id="contents" name="contents">Contents</a></p>
55 <ul class="simple">
56 <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 </ul>
63 </li>
64 <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 </ul>
70 </div>
71 <div class="section">
72 <h1><a class="toc-backref" href="#id3" id="status" name="status">Status</a></h1>
73 <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 </div>
78 <div class="section">
79 <h1><a class="toc-backref" href="#id4" id="abstract" name="abstract">Abstract</a></h1>
80 <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 <div class="section">
86 <h1><a class="toc-backref" href="#id5" id="motivation" name="motivation">Motivation</a></h1>
87 <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 <div class="section">
97 <h1><a class="toc-backref" href="#id6" id="specification" name="specification">Specification</a></h1>
98 <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 will reside in a directory <tt class="docutils literal"><span class="pre">/etc/portage/sets/</span></tt> and each set's name
101 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 <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 <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.
131 emerge --package-set foo # So we specify that what we actually
132 # meant was the package set.
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 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 <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 <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 <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 Masking a package set through the <tt class="docutils literal"><span class="pre">package.mask</span></tt> file is forbidden.
157 In order to 'mask' a package set, one should move it away from the
158 sets directory.</li>
159 <li>package.use:
160 USE flags may not be defined for sets in the <tt class="docutils literal"><span class="pre">package.use</span></tt> file.</li>
161 </ul>
162 </div>
163 </div>
164 <div class="section">
165 <h1><a class="toc-backref" href="#id9" id="implementation" name="implementation">Implementation</a></h1>
166 <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 <div class="section">
174 <h1><a class="toc-backref" href="#id10" id="rationale" name="rationale">Rationale</a></h1>
175 <p>The one file per set approach makes it easy to list the sets which are
176 defined on a system by just listing the <tt class="docutils literal"><span class="pre">/etc/portage/sets</span></tt>
177 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 <p>Allowing sets' USE flags to be manipulated through the <tt class="docutils literal"><span class="pre">package.use</span></tt>
183 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 <div class="section">
199 <h1><a class="toc-backref" href="#id11" id="backwards-compatibility" name="backwards-compatibility">Backwards Compatibility</a></h1>
200 <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 <tt class="docutils literal"><span class="pre">/etc/portage/sets/</span></tt> directory.</li>
207 </ol>
208 <p>Other than that, there are no other backwards compatibility concerns
209 involved.</p>
210 </div>
211 <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 <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 <table class="docutils footnote" frame="void" id="portage-manpage" rules="none">
221 <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 <div class="section">
228 <h1><a class="toc-backref" href="#id13" id="copyright" name="copyright">Copyright</a></h1>
229 <p>This document has been placed in the public domain.</p>
230 </div>
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