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1 <?xml version='1.0' encoding='UTF-8'?>
2 <!DOCTYPE sections SYSTEM "/dtd/book.dtd">
3
4 <!-- The content of this document is licensed under the CC-BY-SA license -->
5 <!-- See http://creativecommons.org/licenses/by-sa/2.0 -->
6
7 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/handbook/hb-working-portage.xml,v 1.39 2004/10/21 10:31:20 swift Exp $ -->
8
9 <sections>
10 <section>
11 <title>Welcome to Portage</title>
12 <body>
13
14 <p>
15 Portage is probably Gentoo's most notable innovation in software management.
16 With its high flexibility and enormous amount of features it is frequently seen
17 as the best software management tool available for Linux.
18 </p>
19
20 <p>
21 Portage is completely written in <uri link="http://www.python.org">Python</uri>
22 and <uri link="http://www.gnu.org/software/bash">Bash</uri> and therefore fully
23 visible to the users as both are scripting languages.
24 </p>
25
26 <p>
27 Most users will work with Portage through the <c>emerge</c> tool. This chapter
28 is not meant to duplicate the information available from the emerge man page.
29 For a complete rundown of emerge's options, please consult the man page:
30 </p>
31
32 <pre caption="Reading the emerge man page">
33 $ <i>man emerge</i>
34 </pre>
35
36 </body>
37 </section>
38 <section>
39 <title>The Portage Tree</title>
40 <subsection>
41 <title>Ebuilds</title>
42 <body>
43
44 <p>
45 When we talk about packages, we often mean software titles that are available to
46 the Gentoo users through the Portage tree. The Portage tree is a collection of
47 <e>ebuilds</e>, files that contain all information Portage needs to maintain
48 software (install, search, query, ...). These ebuilds reside in
49 <path>/usr/portage</path> by default.
50 </p>
51
52 <p>
53 Whenever you ask Portage to perform some action regarding software titles, it
54 will use the ebuilds on your system as a base. It is therefore important that
55 you regularly update the ebuilds on your system so Portage knows about new
56 software, security updates, etc.
57 </p>
58
59 </body>
60 </subsection>
61 <subsection>
62 <title>Updating the Portage Tree</title>
63 <body>
64
65 <p>
66 The Portage tree is usually updated with <uri
67 link="http://rsync.gentoo.org">rsync</uri>, a fast incremental file transfer
68 utility. Updating is fairly simple as the <c>emerge</c> command provides a
69 front-end for rsync:
70 </p>
71
72 <pre caption="Updating the Portage tree">
73 # <i>emerge --sync</i>
74 </pre>
75
76 <p>
77 If you are unable to rsync due to firewall restrictions you can still update
78 your Portage tree by using our daily generated Portage tree snapshots. The
79 <c>emerge-webrsync</c> tool automatically fetches and installs the latest
80 snapshot on your system:
81 </p>
82
83 <pre caption="Running emerge-webrsync">
84 # <i>emerge-webrsync</i>
85 </pre>
86
87 </body>
88 </subsection>
89 </section>
90 <section>
91 <title>Maintaining Software</title>
92 <subsection>
93 <title>Searching for Software</title>
94 <body>
95
96 <p>
97 To search through the Portage tree after software titles, you can use
98 <c>emerge</c> built-in search capabilities. By default, <c>emerge search</c>
99 returns package names whos title corresponds with (either fully or partially)
100 the given search term.
101 </p>
102
103 <p>
104 For instance, to search for all packages who have "pdf" in their name:
105 </p>
106
107 <pre caption="Searching for pdf-named packages">
108 $ <i>emerge search pdf</i>
109 </pre>
110
111 <p>
112 If you want to search through the descriptions as well you can use the
113 <c>--searchdesc</c> (or <c>-S</c>) switch:
114 </p>
115
116 <pre caption="Searching for pdf-related packages">
117 $ <i>emerge --searchdesc pdf</i>
118 </pre>
119
120 <p>
121 When you take a look at the output, you'll notice that it gives you a lot of
122 information. The fields are clearly labelled so we won't go further into their
123 meanings:
124 </p>
125
126 <pre caption="Example emerge search output">
127 * net-print/cups-pdf
128 Latest version available: 1.5.2
129 Latest version installed: [ Not Installed ]
130 Size of downloaded files: 15 kB
131 Homepage: http://cip.physik.uni-wuerzburg.de/~vrbehr/cups-pdf/
132 Description: Provides a virtual printer for CUPS to produce PDF files.
133 License: GPL-2
134 </pre>
135
136 </body>
137 </subsection>
138 <subsection>
139 <title>Installing Software</title>
140 <body>
141
142 <p>
143 Once you've found a software title to your liking, you can easily install it
144 with <c>emerge</c>: just add the package name. For instance, to install
145 <c>gnumeric</c>:
146 </p>
147
148 <pre caption="Installing gnumeric">
149 # <i>emerge gnumeric</i>
150 </pre>
151
152 <p>
153 Since many applications depend on each other, any attempt to install a certain
154 software package might result in the installation of several dependencies as
155 well. Don't worry, Portage handles dependencies well. If you want to find out
156 what Portage <e>would</e> install when you ask it to install a certain package,
157 add the <c>--pretend</c> switch. For instance:
158 </p>
159
160 <pre caption="Pretend to install gnumeric">
161 # <i>emerge --pretend gnumeric</i>
162 </pre>
163
164 <p>
165 When you ask Portage to install a package, it will download the necessary source
166 code from the internet (if necessary) and store it by default in
167 <path>/usr/portage/distfiles</path>. After this it will unpack, compile and
168 install the package. If you want Portage to only download the sources without
169 installing them, add the <c>--fetchonly</c> option to the <c>emerge</c> command:
170 </p>
171
172 <pre caption="Download the sourcecode for gnumeric">
173 # <i>emerge --fetchonly gnumeric</i>
174 </pre>
175
176 </body>
177 </subsection>
178 <subsection>
179 <title>Removing Software</title>
180 <body>
181
182 <p>
183 When you want to remove a software package from your system, use <c>emerge
184 unmerge</c>. This will tell Portage to remove all files installed by that
185 package from your system <e>except</e> the configuration files of that
186 application if you have altered those after the installation. Leaving the
187 configuration files allows you to continue working with the package if you ever
188 decide to install it again.
189 </p>
190
191 <p>
192 However, a <brite>big warning</brite> applies: Portage will <e>not</e> check if
193 the package you want to remove is required by another package. It will however
194 warn you when you want to remove an important package that breaks your system
195 if you unmerge it.
196 </p>
197
198 <pre caption="Removing gnumeric from the system">
199 # <i>emerge unmerge gnumeric</i>
200 </pre>
201
202 <p>
203 When you remove a package from your system, the dependencies of that package
204 that were installed automatically when you installed the software are left. To
205 have Portage locate all dependencies that can now be removed, use
206 <c>emerge</c>'s <c>depclean</c> functionality. We will talk about this later on.
207 </p>
208
209 </body>
210 </subsection>
211 <subsection>
212 <title>Updating your System</title>
213 <body>
214
215 <p>
216 To keep your system in perfect shape (and not to mention install the latest
217 security updates) you need to update your system regularly. Since Portage only
218 checks the ebuilds in your Portage tree you first have to update your Portage
219 tree. When your Portage tree is updated, you can update your system with
220 <c>emerge --update world</c>:
221 </p>
222
223 <pre caption="Updating your system">
224 # <i>emerge --update world</i>
225 </pre>
226
227 <p>
228 Portage will then search for newer version of the applications you have
229 installed. However, it will only verify the versions for the applications you
230 have explicitly installed - not the dependencies. If you want to update every
231 single package on your system, add the <c>--deep</c> argument:
232 </p>
233
234 <pre caption="Updating your entire system">
235 # <i>emerge --update --deep world</i>
236 </pre>
237
238 <p>
239 If you have altered any of your <uri link="?part=2&amp;chap=2">USE flags</uri>
240 lately you might want to add <c>--newuse</c> as well. Portage will then verify
241 if the change requires the installation of new packages or recompilation of
242 existing ones:
243 </p>
244
245 <pre caption="Performing a full update">
246 # <i>emerge --update --deep --newuse world</i>
247 </pre>
248
249 </body>
250 </subsection>
251 <subsection>
252 <title>Stub Packages</title>
253 <body>
254
255 <p>
256 Some packages in the Portage tree don't have any real content but are used to
257 install a collection of packages. For instance, the <c>kde</c> package will
258 install a complete KDE environment on your system by pulling in various
259 KDE-related packages as dependencies.
260 </p>
261
262 <p>
263 If you ever want to remove such a package from your system, running <c>emerge
264 unmerge</c> on the package won't have much effect as the dependencies remain on
265 the system.
266 </p>
267
268 <p>
269 Portage has the functionality to remove orphaned dependencies as well, but since
270 the availability of software is dynamically dependent you first need to update
271 your entire system fully, including the new changes you applied when changing
272 USE flags. After this you can run <c>emerge depclean</c> to remove the orphaned
273 dependencies. When this is done, you need to rebuild the applications that were
274 dynamically linked to the now-removed software titles but don't require them
275 anymore.
276 </p>
277
278 <p>
279 All this is handled with the following three commands:
280 </p>
281
282 <pre caption="Removing orphaned dependencies">
283 # <i>emerge --update --deep --newuse world</i>
284 # <i>emerge depclean</i>
285 # <i>revdep-rebuild</i>
286 </pre>
287
288 <p>
289 <c>revdep-rebuild</c> is provided by the <c>gentoolkit</c> package; don't forget
290 to emerge it first:
291 </p>
292
293 <pre caption="Installing the gentoolkit package">
294 # <i>emerge gentoolkit</i>
295 </pre>
296
297 </body>
298 </subsection>
299 </section>
300 <section>
301 <title>When Portage is Complaining...</title>
302 <subsection>
303 <title>About SLOTs, Virtuals, Branches, Architectures and Profiles</title>
304 <body>
305
306 <p>
307 As we stated before, Portage is extremely powerful and supports many features
308 that other software management tools lack. To understand this, we explain a few
309 aspects of Portage without going in too much detail.
310 </p>
311
312 <p>
313 With Portage different versions of a single package can coexist on a system.
314 While other distributions tend to name their package to those versions (like
315 <c>freetype</c> and <c>freetype2</c>) Portage uses a technology called
316 <e>SLOT</e>s. An ebuild declares a certain SLOT for its version. Ebuilds with
317 different SLOTs can coexist on the same system. For instance, the
318 <c>freetype</c> package has ebuilds with <c>SLOT="1"</c> and <c>SLOT="2"</c>.
319 </p>
320
321 <p>
322 There are also packages that provide the same functionality but are implemented
323 differently. For instance, <c>metalogd</c>, <c>sysklogd</c> and <c>syslog-ng</c>
324 are all system loggers. Applications that rely on the availability of "a system
325 logger" cannot depend on, for instance, <c>metalogd</c>, as the other system
326 loggers are as good a choice as any. Portage allows for <e>virtuals</e>: each
327 system logger provides <c>virtual/syslog</c> so that applications can depend on
328 <c>virtual/syslog</c>.
329 </p>
330
331 <p>
332 Software in the Portage tree can reside in different branches. By default your
333 system only accepts packages that Gentoo deems stable. Most new software titles,
334 when committed, are added to the testing branch, meaning more testing needs to
335 be done before it is marked as stable. Although you will see the ebuilds for
336 those software in the Portage tree, Portage will not update them before they are
337 placed in the stable branch.
338 </p>
339
340 <p>
341 Some software is only available for a few architectures. Or the software doesn't
342 work on the other architectures, or it needs more testing, or the developer that
343 committed the software to the Portage tree is unable to verify if the package
344 works on different architectures.
345 </p>
346
347 <p>
348 Each Gentoo installation adheres to a certain <c>profile</c> which contains,
349 amongst other information, the list of packages that are required for a system
350 to function normally.
351 </p>
352
353 </body>
354 </subsection>
355 <subsection id="blocked">
356 <title>Blocked Packages</title>
357 <body>
358
359 <pre caption="Portage warning about blocked packages (with --pretend)">
360 [blocks B ] gnome-base/bonobo-activation (from pkg gnome-base/libbonobo-2.4.0)
361 </pre>
362
363 <pre caption="Portage warning about blocked packages (without --pretend)">
364 !!! Error: the gnome-base/bonobo-activation package conflicts with another package.
365 !!! both can't be installed on the same system together.
366 !!! Please use 'emerge --pretend' to determine blockers.
367 </pre>
368
369 <p>
370 Ebuilds contain specific fields that inform Portage about it's dependencies.
371 There are two possible dependencies: build dependencies, declared in
372 <c>DEPEND</c> and run-time dependencies, declared in <c>RDEPEND</c>. When one of
373 these dependencies explicitly marks a package or virtual as being <e>not</e>
374 compatible, it triggers a blockage.
375 </p>
376
377 <p>
378 To fix a blockage, you can choose to not install the package or unmerge the
379 conflicting package first. In the given example, you can opt not to install
380 <c>libbonobo</c> or to remove <c>bonobo-activation</c> first.
381 </p>
382
383 </body>
384 </subsection>
385 <subsection id="masked">
386 <title>Masked Packages</title>
387 <body>
388
389 <pre caption="Portage warning about masked packages">
390 !!! all ebuilds that could satisfy "bootsplash" have been masked.
391 </pre>
392
393 <pre caption="Portage warning about masked packages - reason">
394 !!! possible candidates are:
395
396 - gnome-base/gnome-2.8.0_pre1 (masked by: <i>~x86 keyword</i>)
397 - lm-sensors/lm-sensors-2.8.7 (masked by: <i>-sparc keyword</i>)
398 - sys-libs/glibc-2.3.4.20040808 (masked by: <i>-* keyword</i>)
399 - dev-util/cvsd-1.0.2 (masked by: <i>missing keyword</i>)
400 - media-video/ati-gatos-4.3.0 (masked by: <i>package.mask</i>)
401 - sys-libs/glibc-2.3.2-r11 (masked by: <i>profile</i>)
402 </pre>
403
404 <p>
405 When you want to install a package that isn't available for your system, you
406 will receive this masking error. You should try installing a different
407 application that is available for your system or wait until the package is put
408 available. There is always a reason why a package is masked:
409 </p>
410
411 <ul>
412 <li>
413 <b>~arch keyword</b> means that the application is not tested sufficiently
414 to be put in the stable branch. Wait a few days or weeks and try again.
415 </li>
416 <li>
417 <b>-arch keyword</b> or <b>-* keyword</b> means that the application does
418 not work on your architecture. If you believe the package does work file
419 a bug at our <uri link="http://bugs.gentoo.org">bugzilla</uri> website.
420 </li>
421 <li>
422 <b>missing keyword</b> means that the application has not been tested on
423 your architecture yet. Ask the architecture porting team to test the package
424 or test it for them and report your findings on our <uri
425 link="http://bugs.gentoo.org">bugzilla</uri> website.
426 </li>
427 <li>
428 <b>package.mask</b> means that the package has been found corrupt, unstable
429 or worse and has been deliberately marked as do-not-use.
430 </li>
431 <li>
432 <b>profile</b> means that the package has been found not suitable for your
433 profile. The application might break your system if you installed it or is
434 just not compatible with the profile you use.
435 </li>
436 </ul>
437
438 </body>
439 </subsection>
440 <subsection id="missingdependencies">
441 <title>Missing Dependencies</title>
442 <body>
443
444 <pre caption="Portage warning about missing dependency">
445 emerge: there are no ebuilds to satisfy "&gt;=sys-devel/gcc-4.2-r4".
446
447 !!! Problem with ebuild sys-devel/gcc-3.4.2-r2
448 !!! Possibly a DEPEND/*DEPEND problem.
449 </pre>
450
451 <p>
452 The application you are trying to install depends on another package that is not
453 available for your system. Please check <uri
454 link="http://bugs.gentoo.org">bugzilla</uri> if the issue is known and if not,
455 please report it. Unless you are mixing branches this should not occur and is
456 therefore a bug.
457 </p>
458
459 </body>
460 </subsection>
461 <subsection id="ambiguousebuild">
462 <title>Ambiguous Ebuild Name</title>
463 <body>
464
465 <pre caption="Portage warning about ambiguous ebuild names">
466 !!! The short ebuild name "aterm" is ambiguous. Please specify
467 !!! one of the following fully-qualified ebuild names instead:
468
469 dev-libs/aterm
470 x11-terms/aterm
471 </pre>
472
473 <p>
474 The application you want to install has a name that corresponds with more than
475 one package. You need to supply the category name as well. Portage will inform
476 you of possible matches to choose from.
477 </p>
478
479 </body>
480 </subsection>
481 <subsection id="circulardependencies">
482 <title>Circular Dependencies</title>
483 <body>
484
485 <pre caption="Portage warning about circular dependencies">
486 !!! Error: circular dependencies:
487
488 ebuild / net-print/cups-1.1.15-r2 depends on ebuild / app-text/ghostscript-7.05.3-r1
489 ebuild / app-text/ghostscript-7.05.3-r1 depends on ebuild / net-print/cups-1.1.15-r2
490 </pre>
491
492 <p>
493 Two (or more) packages you want to install depend on each other and can
494 therefore not be installed. This is most likely a bug in the Portage tree.
495 Please resync after a while and try again. You can also check <uri
496 link="http://bugs.gentoo.org">bugzilla</uri> if the issue is known and if not,
497 report it.
498 </p>
499
500 </body>
501 </subsection>
502 <subsection id="fetchfailed">
503 <title>Fetch failed</title>
504 <body>
505
506 <pre caption="Portage warning about fetch failed">
507 !!! Fetch failed for sys-libs/ncurses-5.4-r5, continuing...
508 <comment>(...)</comment>
509 !!! Some fetch errors were encountered. Please see above for details.
510 </pre>
511
512 <p>
513 Portage was unable to download the sources for the given application and will
514 try to continue installing the other applications (if applicable). This failure
515 can be due to a mirror that has not synchronised correctly or because the ebuild
516 points to an incorrect location. The server where the sources reside can also be
517 down for some reason.
518 </p>
519
520 <p>
521 Retry after one hour to see if the issue still persists.
522 </p>
523
524 </body>
525 </subsection>
526 <subsection id="profileprotect">
527 <title>System Profile Protection</title>
528 <body>
529
530 <pre caption="Portage warning about profile-protected package">
531 !!! Trying to unmerge package(s) in system profile. 'sys-apps/portage'
532 !!! This could be damaging to your system.
533 </pre>
534
535 <p>
536 You have asked to remove a package that is part of your system's core packages.
537 It is listed in your profile as required and should therefore not be removed
538 from the system.
539 </p>
540
541 </body>
542 </subsection>
543 </section>
544 </sections>

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