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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 1.55 2005/06/24 19:28:48 fox2mike Exp $ -->
8
9 <sections>
10
11 <version>1.51</version>
12 <date>2005-06-30</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>:
278 </p>
279
280 <pre caption="Updating your system">
281 # <i>emerge --update world</i>
282 </pre>
283
284 <p>
285 Portage will then search for newer version of the applications you have
286 installed. However, it will only verify the versions for the applications you
287 have explicitly installed - not the dependencies. If you want to update every
288 single package on your system, add the <c>--deep</c> argument:
289 </p>
290
291 <pre caption="Updating your entire system">
292 # <i>emerge --update --deep world</i>
293 </pre>
294
295 <p>
296 Since security updates also happen in packages you have not explicitly installed
297 on your system (but that are pulled in as dependencies of other programs), it
298 is recommended to run this command once in a while.
299 </p>
300
301 <p>
302 If you have altered any of your <uri link="?part=2&amp;chap=2">USE flags</uri>
303 lately you might want to add <c>--newuse</c> as well. Portage will then verify
304 if the change requires the installation of new packages or recompilation of
305 existing ones:
306 </p>
307
308 <pre caption="Performing a full update">
309 # <i>emerge --update --deep --newuse world</i>
310 </pre>
311
312 </body>
313 </subsection>
314 <subsection>
315 <title>Metapackages</title>
316 <body>
317
318 <p>
319 Some packages in the Portage tree don't have any real content but are used to
320 install a collection of packages. For instance, the <c>kde</c> package will
321 install a complete KDE environment on your system by pulling in various
322 KDE-related packages as dependencies.
323 </p>
324
325 <p>
326 If you ever want to remove such a package from your system, running <c>emerge
327 --unmerge</c> on the package won't have much effect as the dependencies remain
328 on the system.
329 </p>
330
331 <p>
332 Portage has the functionality to remove orphaned dependencies as well, but since
333 the availability of software is dynamically dependent you first need to update
334 your entire system fully, including the new changes you applied when changing
335 USE flags. After this you can run <c>emerge --depclean</c> to remove the
336 orphaned dependencies. When this is done, you need to rebuild the applications
337 that were dynamically linked to the now-removed software titles but don't
338 require them anymore.
339 </p>
340
341 <p>
342 All this is handled with the following three commands:
343 </p>
344
345 <pre caption="Removing orphaned dependencies">
346 # <i>emerge --update --deep --newuse world</i>
347 # <i>emerge --depclean</i>
348 # <i>revdep-rebuild</i>
349 </pre>
350
351 <p>
352 <c>revdep-rebuild</c> is provided by the <c>gentoolkit</c> package; don't forget
353 to emerge it first:
354 </p>
355
356 <pre caption="Installing the gentoolkit package">
357 # <i>emerge gentoolkit</i>
358 </pre>
359
360 </body>
361 </subsection>
362 </section>
363 <section>
364 <title>When Portage is Complaining...</title>
365 <subsection>
366 <title>About SLOTs, Virtuals, Branches, Architectures and Profiles</title>
367 <body>
368
369 <p>
370 As we stated before, Portage is extremely powerful and supports many features
371 that other software management tools lack. To understand this, we explain a few
372 aspects of Portage without going into too much detail.
373 </p>
374
375 <p>
376 With Portage different versions of a single package can coexist on a system.
377 While other distributions tend to name their package to those versions (like
378 <c>freetype</c> and <c>freetype2</c>) Portage uses a technology called
379 <e>SLOT</e>s. An ebuild declares a certain SLOT for its version. Ebuilds with
380 different SLOTs can coexist on the same system. For instance, the
381 <c>freetype</c> package has ebuilds with <c>SLOT="1"</c> and <c>SLOT="2"</c>.
382 </p>
383
384 <p>
385 There are also packages that provide the same functionality but are implemented
386 differently. For instance, <c>metalogd</c>, <c>sysklogd</c> and <c>syslog-ng</c>
387 are all system loggers. Applications that rely on the availability of "a system
388 logger" cannot depend on, for instance, <c>metalogd</c>, as the other system
389 loggers are as good a choice as any. Portage allows for <e>virtuals</e>: each
390 system logger provides <c>virtual/syslog</c> so that applications can depend on
391 <c>virtual/syslog</c>.
392 </p>
393
394 <p>
395 Software in the Portage tree can reside in different branches. By default your
396 system only accepts packages that Gentoo deems stable. Most new software titles,
397 when committed, are added to the testing branch, meaning more testing needs to
398 be done before it is marked as stable. Although you will see the ebuilds for
399 those software in the Portage tree, Portage will not update them before they are
400 placed in the stable branch.
401 </p>
402
403 <p>
404 Some software is only available for a few architectures. Or the software doesn't
405 work on the other architectures, or it needs more testing, or the developer that
406 committed the software to the Portage tree is unable to verify if the package
407 works on different architectures.
408 </p>
409
410 <p>
411 Each Gentoo installation adheres to a certain <c>profile</c> which contains,
412 amongst other information, the list of packages that are required for a system
413 to function normally.
414 </p>
415
416 </body>
417 </subsection>
418 <subsection id="blocked">
419 <title>Blocked Packages</title>
420 <body>
421
422 <pre caption="Portage warning about blocked packages (with --pretend)">
423 [blocks B ] mail-mta/ssmtp (is blocking mail-mta/postfix-2.2.2-r1)
424 </pre>
425
426 <pre caption="Portage warning about blocked packages (without --pretend)">
427 !!! Error: the mail-mta/postfix package conflicts with another package.
428 !!! both can't be installed on the same system together.
429 !!! Please use 'emerge --pretend' to determine blockers.
430 </pre>
431
432 <p>
433 Ebuilds contain specific fields that inform Portage about its dependencies.
434 There are two possible dependencies: build dependencies, declared in
435 <c>DEPEND</c> and run-time dependencies, declared in <c>RDEPEND</c>. When one of
436 these dependencies explicitly marks a package or virtual as being <e>not</e>
437 compatible, it triggers a blockage.
438 </p>
439
440 <p>
441 To fix a blockage, you can choose to not install the package or unmerge the
442 conflicting package first. In the given example, you can opt not to install
443 <c>postfix</c> or to remove <c>ssmtp</c> first.
444 </p>
445
446 <p>
447 It is also possible that two packages that are yet to be installed are blocking
448 each other. In this rare case, you should find out why you need to install both.
449 In most cases you can do with one of the packages alone. If not, please file a
450 bug on <uri link="http://bugs.gentoo.org">Gentoo's bugtracking system</uri>.
451 </p>
452
453 </body>
454 </subsection>
455 <subsection id="masked">
456 <title>Masked Packages</title>
457 <body>
458
459 <pre caption="Portage warning about masked packages">
460 !!! all ebuilds that could satisfy "bootsplash" have been masked.
461 </pre>
462
463 <pre caption="Portage warning about masked packages - reason">
464 !!! possible candidates are:
465
466 - gnome-base/gnome-2.8.0_pre1 (masked by: <i>~x86 keyword</i>)
467 - lm-sensors/lm-sensors-2.8.7 (masked by: <i>-sparc keyword</i>)
468 - sys-libs/glibc-2.3.4.20040808 (masked by: <i>-* keyword</i>)
469 - dev-util/cvsd-1.0.2 (masked by: <i>missing keyword</i>)
470 - media-video/ati-gatos-4.3.0 (masked by: <i>package.mask</i>)
471 - sys-libs/glibc-2.3.2-r11 (masked by: <i>profile</i>)
472 </pre>
473
474 <p>
475 When you want to install a package that isn't available for your system, you
476 will receive this masking error. You should try installing a different
477 application that is available for your system or wait until the package is put
478 available. There is always a reason why a package is masked:
479 </p>
480
481 <ul>
482 <li>
483 <b>~arch keyword</b> means that the application is not tested sufficiently
484 to be put in the stable branch. Wait a few days or weeks and try again.
485 </li>
486 <li>
487 <b>-arch keyword</b> or <b>-* keyword</b> means that the application does
488 not work on your architecture. If you believe the package does work file
489 a bug at our <uri link="http://bugs.gentoo.org">bugzilla</uri> website.
490 </li>
491 <li>
492 <b>missing keyword</b> means that the application has not been tested on
493 your architecture yet. Ask the architecture porting team to test the package
494 or test it for them and report your findings on our <uri
495 link="http://bugs.gentoo.org">bugzilla</uri> website.
496 </li>
497 <li>
498 <b>package.mask</b> means that the package has been found corrupt, unstable
499 or worse and has been deliberately marked as do-not-use.
500 </li>
501 <li>
502 <b>profile</b> means that the package has been found not suitable for your
503 profile. The application might break your system if you installed it or is
504 just not compatible with the profile you use.
505 </li>
506 </ul>
507
508 </body>
509 </subsection>
510 <subsection id="missingdependencies">
511 <title>Missing Dependencies</title>
512 <body>
513
514 <pre caption="Portage warning about missing dependency">
515 emerge: there are no ebuilds to satisfy "&gt;=sys-devel/gcc-3.4.2-r4".
516
517 !!! Problem with ebuild sys-devel/gcc-3.4.2-r2
518 !!! Possibly a DEPEND/*DEPEND problem.
519 </pre>
520
521 <p>
522 The application you are trying to install depends on another package that is not
523 available for your system. Please check <uri
524 link="http://bugs.gentoo.org">bugzilla</uri> if the issue is known and if not,
525 please report it. Unless you are mixing branches this should not occur and is
526 therefore a bug.
527 </p>
528
529 </body>
530 </subsection>
531 <subsection id="ambiguousebuild">
532 <title>Ambiguous Ebuild Name</title>
533 <body>
534
535 <pre caption="Portage warning about ambiguous ebuild names">
536 !!! The short ebuild name "aterm" is ambiguous. Please specify
537 !!! one of the following fully-qualified ebuild names instead:
538
539 dev-libs/aterm
540 x11-terms/aterm
541 </pre>
542
543 <p>
544 The application you want to install has a name that corresponds with more than
545 one package. You need to supply the category name as well. Portage will inform
546 you of possible matches to choose from.
547 </p>
548
549 </body>
550 </subsection>
551 <subsection id="circulardependencies">
552 <title>Circular Dependencies</title>
553 <body>
554
555 <pre caption="Portage warning about circular dependencies">
556 !!! Error: circular dependencies:
557
558 ebuild / net-print/cups-1.1.15-r2 depends on ebuild / app-text/ghostscript-7.05.3-r1
559 ebuild / app-text/ghostscript-7.05.3-r1 depends on ebuild / net-print/cups-1.1.15-r2
560 </pre>
561
562 <p>
563 Two (or more) packages you want to install depend on each other and can
564 therefore not be installed. This is most likely a bug in the Portage tree.
565 Please resync after a while and try again. You can also check <uri
566 link="http://bugs.gentoo.org">bugzilla</uri> if the issue is known and if not,
567 report it.
568 </p>
569
570 </body>
571 </subsection>
572 <subsection id="fetchfailed">
573 <title>Fetch failed</title>
574 <body>
575
576 <pre caption="Portage warning about fetch failed">
577 !!! Fetch failed for sys-libs/ncurses-5.4-r5, continuing...
578 <comment>(...)</comment>
579 !!! Some fetch errors were encountered. Please see above for details.
580 </pre>
581
582 <p>
583 Portage was unable to download the sources for the given application and will
584 try to continue installing the other applications (if applicable). This failure
585 can be due to a mirror that has not synchronised correctly or because the ebuild
586 points to an incorrect location. The server where the sources reside can also be
587 down for some reason.
588 </p>
589
590 <p>
591 Retry after one hour to see if the issue still persists.
592 </p>
593
594 </body>
595 </subsection>
596 <subsection id="profileprotect">
597 <title>System Profile Protection</title>
598 <body>
599
600 <pre caption="Portage warning about profile-protected package">
601 !!! Trying to unmerge package(s) in system profile. 'sys-apps/portage'
602 !!! This could be damaging to your system.
603 </pre>
604
605 <p>
606 You have asked to remove a package that is part of your system's core packages.
607 It is listed in your profile as required and should therefore not be removed
608 from the system.
609 </p>
610
611 </body>
612 </subsection>
613 </section>
614 </sections>

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