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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/2.5 -->
6
7 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/handbook/hb-working-portage.xml,v 1.56 2005/06/30 07:44:34 swift Exp $ -->
8
9 <sections>
10
11 <version>1.52</version>
12 <date>2005-12-26</date>
13
14 <section>
15 <title>Welcome to Portage</title>
16 <body>
17
18 <p>
19 Portage is probably Gentoo's most notable innovation in software management.
20 With its high flexibility and enormous amount of features it is frequently seen
21 as the best software management tool available for Linux.
22 </p>
23
24 <p>
25 Portage is completely written in <uri link="http://www.python.org">Python</uri>
26 and <uri link="http://www.gnu.org/software/bash">Bash</uri> and therefore fully
27 visible to the users as both are scripting languages.
28 </p>
29
30 <p>
31 Most users will work with Portage through the <c>emerge</c> tool. This chapter
32 is not meant to duplicate the information available from the emerge man page.
33 For a complete rundown of emerge's options, please consult the man page:
34 </p>
35
36 <pre caption="Reading the emerge man page">
37 $ <i>man emerge</i>
38 </pre>
39
40 </body>
41 </section>
42 <section>
43 <title>The Portage Tree</title>
44 <subsection>
45 <title>Ebuilds</title>
46 <body>
47
48 <p>
49 When we talk about packages, we often mean software titles that are available to
50 the Gentoo users through the Portage tree. The Portage tree is a collection of
51 <e>ebuilds</e>, files that contain all information Portage needs to maintain
52 software (install, search, query, ...). These ebuilds reside in
53 <path>/usr/portage</path> by default.
54 </p>
55
56 <p>
57 Whenever you ask Portage to perform some action regarding software titles, it
58 will use the ebuilds on your system as a base. It is therefore important that
59 you regularly update the ebuilds on your system so Portage knows about new
60 software, security updates, etc.
61 </p>
62
63 </body>
64 </subsection>
65 <subsection>
66 <title>Updating the Portage Tree</title>
67 <body>
68
69 <p>
70 The Portage tree is usually updated with <uri
71 link="http://rsync.samba.org/">rsync</uri>, a fast incremental file transfer
72 utility. Updating is fairly simple as the <c>emerge</c> command provides a
73 front-end for rsync:
74 </p>
75
76 <pre caption="Updating the Portage tree">
77 # <i>emerge --sync</i>
78 </pre>
79
80 <p>
81 If you are unable to rsync due to firewall restrictions you can still update
82 your Portage tree by using our daily generated Portage tree snapshots. The
83 <c>emerge-webrsync</c> tool automatically fetches and installs the latest
84 snapshot on your system:
85 </p>
86
87 <pre caption="Running emerge-webrsync">
88 # <i>emerge-webrsync</i>
89 </pre>
90
91 </body>
92 </subsection>
93 </section>
94 <section>
95 <title>Maintaining Software</title>
96 <subsection>
97 <title>Searching for Software</title>
98 <body>
99
100 <p>
101 To search through the Portage tree after software titles, you can use
102 <c>emerge</c> built-in search capabilities. By default, <c>emerge --search</c>
103 returns the names of packages whose title matches (either fully or partially)
104 the given search term.
105 </p>
106
107 <p>
108 For instance, to search for all packages who have "pdf" in their name:
109 </p>
110
111 <pre caption="Searching for pdf-named packages">
112 $ <i>emerge --search pdf</i>
113 </pre>
114
115 <p>
116 If you want to search through the descriptions as well you can use the
117 <c>--searchdesc</c> (or <c>-S</c>) switch:
118 </p>
119
120 <pre caption="Searching for pdf-related packages">
121 $ <i>emerge --searchdesc pdf</i>
122 </pre>
123
124 <p>
125 When you take a look at the output, you'll notice that it gives you a lot of
126 information. The fields are clearly labelled so we won't go further into their
127 meanings:
128 </p>
129
130 <pre caption="Example 'emerge --search' output">
131 * net-print/cups-pdf
132 Latest version available: 1.5.2
133 Latest version installed: [ Not Installed ]
134 Size of downloaded files: 15 kB
135 Homepage: http://cip.physik.uni-wuerzburg.de/~vrbehr/cups-pdf/
136 Description: Provides a virtual printer for CUPS to produce PDF files.
137 License: GPL-2
138 </pre>
139
140 </body>
141 </subsection>
142 <subsection>
143 <title>Installing Software</title>
144 <body>
145
146 <p>
147 Once you've found a software title to your liking, you can easily install it
148 with <c>emerge</c>: just add the package name. For instance, to install
149 <c>gnumeric</c>:
150 </p>
151
152 <pre caption="Installing gnumeric">
153 # <i>emerge gnumeric</i>
154 </pre>
155
156 <p>
157 Since many applications depend on each other, any attempt to install a certain
158 software package might result in the installation of several dependencies as
159 well. Don't worry, Portage handles dependencies well. If you want to find out
160 what Portage <e>would</e> install when you ask it to install a certain package,
161 add the <c>--pretend</c> switch. For instance:
162 </p>
163
164 <pre caption="Pretend to install gnumeric">
165 # <i>emerge --pretend gnumeric</i>
166 </pre>
167
168 <p>
169 When you ask Portage to install a package, it will download the necessary source
170 code from the internet (if necessary) and store it by default in
171 <path>/usr/portage/distfiles</path>. After this it will unpack, compile and
172 install the package. If you want Portage to only download the sources without
173 installing them, add the <c>--fetchonly</c> option to the <c>emerge</c> command:
174 </p>
175
176 <pre caption="Download the sourcecode for gnumeric">
177 # <i>emerge --fetchonly gnumeric</i>
178 </pre>
179
180 </body>
181 </subsection>
182 <subsection>
183 <title>Finding Installed Package Documentation</title>
184 <body>
185
186 <p>
187 Many packages come with their own documentation. Sometimes, the <c>doc</c> USE
188 flag determines whether the package documentation should be installed or not.
189 You can check the existence of a <c>doc</c> USE flag with the <c>emerge -vp
190 &lt;package name&gt;</c> command.
191 </p>
192
193 <pre caption="Checking the existence of a doc USE flag">
194 <comment>(alsa-lib is just an example, of course.)</comment>
195 # <i>emerge -vp alsa-lib</i>
196 [ebuild N ] media-libs/alsa-lib-1.0.9_rc3 +doc -jack 674 kB
197 </pre>
198
199 <p>
200 You can enable or disable the <c>doc</c> USE flag either globally in the
201 <path>/etc/make.conf</path> file or per package in the
202 <path>/etc/portage/package.use</path> file. The <uri
203 link="?part=2&amp;chap=2">USE Flags</uri> chapter covers this aspect in detail.
204 </p>
205
206 <p>
207 Once the package installed, its documentation is generally found in a
208 subdirectory named after the package under the <path>/usr/share/doc</path>
209 directory. You can also list all installed files with the <c>equery</c> tool
210 which is part of the <c>app-portage/gentoolkit</c> <uri
211 link="/doc/en/gentoolkit.xml">package</uri>.
212 </p>
213
214 <pre caption="Locating package documentation">
215 # <i>ls -l /usr/share/doc/alsa-lib-1.0.9_rc3</i>
216 total 28
217 -rw-r--r-- 1 root root 669 May 17 21:54 ChangeLog.gz
218 -rw-r--r-- 1 root root 9373 May 17 21:54 COPYING.gz
219 drwxr-xr-x 2 root root 8560 May 17 21:54 html
220 -rw-r--r-- 1 root root 196 May 17 21:54 TODO.gz
221
222 <comment>(Alternatively, use equery to locate interesting files:)</comment>
223 # <i>equery files alsa-lib | less</i>
224 media-libs/alsa-lib-1.0.9_rc3
225 * Contents of media-libs/alsa-lib-1.0.9_rc3:
226 /usr
227 /usr/bin
228 /usr/bin/alsalisp
229 <comment>(Output truncated)</comment>
230 </pre>
231
232 </body>
233 </subsection>
234 <subsection>
235 <title>Removing Software</title>
236 <body>
237
238 <p>
239 When you want to remove a software package from your system, use <c>emerge
240 --unmerge</c>. This will tell Portage to remove all files installed by that
241 package from your system <e>except</e> the configuration files of that
242 application if you have altered those after the installation. Leaving the
243 configuration files allows you to continue working with the package if you ever
244 decide to install it again.
245 </p>
246
247 <p>
248 However, a <brite>big warning</brite> applies: Portage will <e>not</e> check if
249 the package you want to remove is required by another package. It will however
250 warn you when you want to remove an important package that breaks your system
251 if you unmerge it.
252 </p>
253
254 <pre caption="Removing gnumeric from the system">
255 # <i>emerge --unmerge gnumeric</i>
256 </pre>
257
258 <p>
259 When you remove a package from your system, the dependencies of that package
260 that were installed automatically when you installed the software are left. To
261 have Portage locate all dependencies that can now be removed, use
262 <c>emerge</c>'s <c>--depclean</c> functionality. We will talk about this later
263 on.
264 </p>
265
266 </body>
267 </subsection>
268 <subsection>
269 <title>Updating your System</title>
270 <body>
271
272 <p>
273 To keep your system in perfect shape (and not to mention install the latest
274 security updates) you need to update your system regularly. Since Portage only
275 checks the ebuilds in your Portage tree you first have to update your Portage
276 tree. When your Portage tree is updated, you can update your system with
277 <c>emerge --update world</c>. In the next example, we'll also use the
278 <c>--ask</c> switch which will tell Portage to display the list of packages it
279 wants to upgrade and ask you if you want to continue:
280 </p>
281
282 <pre caption="Updating your system">
283 # <i>emerge --update --ask world</i>
284 </pre>
285
286 <p>
287 Portage will then search for newer version of the applications you have
288 installed. However, it will only verify the versions for the applications you
289 have explicitly installed - not the dependencies. If you want to update every
290 single package on your system, add the <c>--deep</c> argument:
291 </p>
292
293 <pre caption="Updating your entire system">
294 # <i>emerge --update --deep world</i>
295 </pre>
296
297 <p>
298 Since security updates also happen in packages you have not explicitly installed
299 on your system (but that are pulled in as dependencies of other programs), it
300 is recommended to run this command once in a while.
301 </p>
302
303 <p>
304 If you have altered any of your <uri link="?part=2&amp;chap=2">USE flags</uri>
305 lately you might want to add <c>--newuse</c> as well. Portage will then verify
306 if the change requires the installation of new packages or recompilation of
307 existing ones:
308 </p>
309
310 <pre caption="Performing a full update">
311 # <i>emerge --update --deep --newuse world</i>
312 </pre>
313
314 </body>
315 </subsection>
316 <subsection>
317 <title>Metapackages</title>
318 <body>
319
320 <p>
321 Some packages in the Portage tree don't have any real content but are used to
322 install a collection of packages. For instance, the <c>kde</c> package will
323 install a complete KDE environment on your system by pulling in various
324 KDE-related packages as dependencies.
325 </p>
326
327 <p>
328 If you ever want to remove such a package from your system, running <c>emerge
329 --unmerge</c> on the package won't have much effect as the dependencies remain
330 on the system.
331 </p>
332
333 <p>
334 Portage has the functionality to remove orphaned dependencies as well, but since
335 the availability of software is dynamically dependent you first need to update
336 your entire system fully, including the new changes you applied when changing
337 USE flags. After this you can run <c>emerge --depclean</c> to remove the
338 orphaned dependencies. When this is done, you need to rebuild the applications
339 that were dynamically linked to the now-removed software titles but don't
340 require them anymore.
341 </p>
342
343 <p>
344 All this is handled with the following three commands:
345 </p>
346
347 <pre caption="Removing orphaned dependencies">
348 # <i>emerge --update --deep --newuse world</i>
349 # <i>emerge --depclean</i>
350 # <i>revdep-rebuild</i>
351 </pre>
352
353 <p>
354 <c>revdep-rebuild</c> is provided by the <c>gentoolkit</c> package; don't forget
355 to emerge it first:
356 </p>
357
358 <pre caption="Installing the gentoolkit package">
359 # <i>emerge gentoolkit</i>
360 </pre>
361
362 </body>
363 </subsection>
364 </section>
365 <section>
366 <title>When Portage is Complaining...</title>
367 <subsection>
368 <title>About SLOTs, Virtuals, Branches, Architectures and Profiles</title>
369 <body>
370
371 <p>
372 As we stated before, Portage is extremely powerful and supports many features
373 that other software management tools lack. To understand this, we explain a few
374 aspects of Portage without going into too much detail.
375 </p>
376
377 <p>
378 With Portage different versions of a single package can coexist on a system.
379 While other distributions tend to name their package to those versions (like
380 <c>freetype</c> and <c>freetype2</c>) Portage uses a technology called
381 <e>SLOT</e>s. An ebuild declares a certain SLOT for its version. Ebuilds with
382 different SLOTs can coexist on the same system. For instance, the
383 <c>freetype</c> package has ebuilds with <c>SLOT="1"</c> and <c>SLOT="2"</c>.
384 </p>
385
386 <p>
387 There are also packages that provide the same functionality but are implemented
388 differently. For instance, <c>metalogd</c>, <c>sysklogd</c> and <c>syslog-ng</c>
389 are all system loggers. Applications that rely on the availability of "a system
390 logger" cannot depend on, for instance, <c>metalogd</c>, as the other system
391 loggers are as good a choice as any. Portage allows for <e>virtuals</e>: each
392 system logger provides <c>virtual/syslog</c> so that applications can depend on
393 <c>virtual/syslog</c>.
394 </p>
395
396 <p>
397 Software in the Portage tree can reside in different branches. By default your
398 system only accepts packages that Gentoo deems stable. Most new software titles,
399 when committed, are added to the testing branch, meaning more testing needs to
400 be done before it is marked as stable. Although you will see the ebuilds for
401 those software in the Portage tree, Portage will not update them before they are
402 placed in the stable branch.
403 </p>
404
405 <p>
406 Some software is only available for a few architectures. Or the software doesn't
407 work on the other architectures, or it needs more testing, or the developer that
408 committed the software to the Portage tree is unable to verify if the package
409 works on different architectures.
410 </p>
411
412 <p>
413 Each Gentoo installation adheres to a certain <c>profile</c> which contains,
414 amongst other information, the list of packages that are required for a system
415 to function normally.
416 </p>
417
418 </body>
419 </subsection>
420 <subsection id="blocked">
421 <title>Blocked Packages</title>
422 <body>
423
424 <pre caption="Portage warning about blocked packages (with --pretend)">
425 [blocks B ] mail-mta/ssmtp (is blocking mail-mta/postfix-2.2.2-r1)
426 </pre>
427
428 <pre caption="Portage warning about blocked packages (without --pretend)">
429 !!! Error: the mail-mta/postfix package conflicts with another package.
430 !!! both can't be installed on the same system together.
431 !!! Please use 'emerge --pretend' to determine blockers.
432 </pre>
433
434 <p>
435 Ebuilds contain specific fields that inform Portage about its dependencies.
436 There are two possible dependencies: build dependencies, declared in
437 <c>DEPEND</c> and run-time dependencies, declared in <c>RDEPEND</c>. When one of
438 these dependencies explicitly marks a package or virtual as being <e>not</e>
439 compatible, it triggers a blockage.
440 </p>
441
442 <p>
443 To fix a blockage, you can choose to not install the package or unmerge the
444 conflicting package first. In the given example, you can opt not to install
445 <c>postfix</c> or to remove <c>ssmtp</c> first.
446 </p>
447
448 <p>
449 It is also possible that two packages that are yet to be installed are blocking
450 each other. In this rare case, you should find out why you need to install both.
451 In most cases you can do with one of the packages alone. If not, please file a
452 bug on <uri link="http://bugs.gentoo.org">Gentoo's bugtracking system</uri>.
453 </p>
454
455 </body>
456 </subsection>
457 <subsection id="masked">
458 <title>Masked Packages</title>
459 <body>
460
461 <pre caption="Portage warning about masked packages">
462 !!! all ebuilds that could satisfy "bootsplash" have been masked.
463 </pre>
464
465 <pre caption="Portage warning about masked packages - reason">
466 !!! possible candidates are:
467
468 - gnome-base/gnome-2.8.0_pre1 (masked by: <i>~x86 keyword</i>)
469 - lm-sensors/lm-sensors-2.8.7 (masked by: <i>-sparc keyword</i>)
470 - sys-libs/glibc-2.3.4.20040808 (masked by: <i>-* keyword</i>)
471 - dev-util/cvsd-1.0.2 (masked by: <i>missing keyword</i>)
472 - media-video/ati-gatos-4.3.0 (masked by: <i>package.mask</i>)
473 - sys-libs/glibc-2.3.2-r11 (masked by: <i>profile</i>)
474 </pre>
475
476 <p>
477 When you want to install a package that isn't available for your system, you
478 will receive this masking error. You should try installing a different
479 application that is available for your system or wait until the package is put
480 available. There is always a reason why a package is masked:
481 </p>
482
483 <ul>
484 <li>
485 <b>~arch keyword</b> means that the application is not tested sufficiently
486 to be put in the stable branch. Wait a few days or weeks and try again.
487 </li>
488 <li>
489 <b>-arch keyword</b> or <b>-* keyword</b> means that the application does
490 not work on your architecture. If you believe the package does work file
491 a bug at our <uri link="http://bugs.gentoo.org">bugzilla</uri> website.
492 </li>
493 <li>
494 <b>missing keyword</b> means that the application has not been tested on
495 your architecture yet. Ask the architecture porting team to test the package
496 or test it for them and report your findings on our <uri
497 link="http://bugs.gentoo.org">bugzilla</uri> website.
498 </li>
499 <li>
500 <b>package.mask</b> means that the package has been found corrupt, unstable
501 or worse and has been deliberately marked as do-not-use.
502 </li>
503 <li>
504 <b>profile</b> means that the package has been found not suitable for your
505 profile. The application might break your system if you installed it or is
506 just not compatible with the profile you use.
507 </li>
508 </ul>
509
510 </body>
511 </subsection>
512 <subsection id="missingdependencies">
513 <title>Missing Dependencies</title>
514 <body>
515
516 <pre caption="Portage warning about missing dependency">
517 emerge: there are no ebuilds to satisfy "&gt;=sys-devel/gcc-3.4.2-r4".
518
519 !!! Problem with ebuild sys-devel/gcc-3.4.2-r2
520 !!! Possibly a DEPEND/*DEPEND problem.
521 </pre>
522
523 <p>
524 The application you are trying to install depends on another package that is not
525 available for your system. Please check <uri
526 link="http://bugs.gentoo.org">bugzilla</uri> if the issue is known and if not,
527 please report it. Unless you are mixing branches this should not occur and is
528 therefore a bug.
529 </p>
530
531 </body>
532 </subsection>
533 <subsection id="ambiguousebuild">
534 <title>Ambiguous Ebuild Name</title>
535 <body>
536
537 <pre caption="Portage warning about ambiguous ebuild names">
538 !!! The short ebuild name "aterm" is ambiguous. Please specify
539 !!! one of the following fully-qualified ebuild names instead:
540
541 dev-libs/aterm
542 x11-terms/aterm
543 </pre>
544
545 <p>
546 The application you want to install has a name that corresponds with more than
547 one package. You need to supply the category name as well. Portage will inform
548 you of possible matches to choose from.
549 </p>
550
551 </body>
552 </subsection>
553 <subsection id="circulardependencies">
554 <title>Circular Dependencies</title>
555 <body>
556
557 <pre caption="Portage warning about circular dependencies">
558 !!! Error: circular dependencies:
559
560 ebuild / net-print/cups-1.1.15-r2 depends on ebuild / app-text/ghostscript-7.05.3-r1
561 ebuild / app-text/ghostscript-7.05.3-r1 depends on ebuild / net-print/cups-1.1.15-r2
562 </pre>
563
564 <p>
565 Two (or more) packages you want to install depend on each other and can
566 therefore not be installed. This is most likely a bug in the Portage tree.
567 Please resync after a while and try again. You can also check <uri
568 link="http://bugs.gentoo.org">bugzilla</uri> if the issue is known and if not,
569 report it.
570 </p>
571
572 </body>
573 </subsection>
574 <subsection id="fetchfailed">
575 <title>Fetch failed</title>
576 <body>
577
578 <pre caption="Portage warning about fetch failed">
579 !!! Fetch failed for sys-libs/ncurses-5.4-r5, continuing...
580 <comment>(...)</comment>
581 !!! Some fetch errors were encountered. Please see above for details.
582 </pre>
583
584 <p>
585 Portage was unable to download the sources for the given application and will
586 try to continue installing the other applications (if applicable). This failure
587 can be due to a mirror that has not synchronised correctly or because the ebuild
588 points to an incorrect location. The server where the sources reside can also be
589 down for some reason.
590 </p>
591
592 <p>
593 Retry after one hour to see if the issue still persists.
594 </p>
595
596 </body>
597 </subsection>
598 <subsection id="profileprotect">
599 <title>System Profile Protection</title>
600 <body>
601
602 <pre caption="Portage warning about profile-protected package">
603 !!! Trying to unmerge package(s) in system profile. 'sys-apps/portage'
604 !!! This could be damaging to your system.
605 </pre>
606
607 <p>
608 You have asked to remove a package that is part of your system's core packages.
609 It is listed in your profile as required and should therefore not be removed
610 from the system.
611 </p>
612
613 </body>
614 </subsection>
615 </section>
616 </sections>

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