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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 1.58 2006/08/01 17:35:05 swift Exp $ -->
8
9 <sections>
10
11 <version>1.54</version>
12 <date>2006-09-04</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. You can also create a directory
203 called <path>/etc/portage/package.use</path> and list it in a file inside this
204 directory. The <uri
205 link="?part=2&amp;chap=2">USE Flags</uri> chapter covers this aspect in detail.
206 </p>
207
208 <p>
209 Once the package installed, its documentation is generally found in a
210 subdirectory named after the package under the <path>/usr/share/doc</path>
211 directory. You can also list all installed files with the <c>equery</c> tool
212 which is part of the <c>app-portage/gentoolkit</c> <uri
213 link="/doc/en/gentoolkit.xml">package</uri>.
214 </p>
215
216 <pre caption="Locating package documentation">
217 # <i>ls -l /usr/share/doc/alsa-lib-1.0.9_rc3</i>
218 total 28
219 -rw-r--r-- 1 root root 669 May 17 21:54 ChangeLog.gz
220 -rw-r--r-- 1 root root 9373 May 17 21:54 COPYING.gz
221 drwxr-xr-x 2 root root 8560 May 17 21:54 html
222 -rw-r--r-- 1 root root 196 May 17 21:54 TODO.gz
223
224 <comment>(Alternatively, use equery to locate interesting files:)</comment>
225 # <i>equery files alsa-lib | less</i>
226 media-libs/alsa-lib-1.0.9_rc3
227 * Contents of media-libs/alsa-lib-1.0.9_rc3:
228 /usr
229 /usr/bin
230 /usr/bin/alsalisp
231 <comment>(Output truncated)</comment>
232 </pre>
233
234 </body>
235 </subsection>
236 <subsection>
237 <title>Removing Software</title>
238 <body>
239
240 <p>
241 When you want to remove a software package from your system, use <c>emerge
242 --unmerge</c>. This will tell Portage to remove all files installed by that
243 package from your system <e>except</e> the configuration files of that
244 application if you have altered those after the installation. Leaving the
245 configuration files allows you to continue working with the package if you ever
246 decide to install it again.
247 </p>
248
249 <p>
250 However, a <brite>big warning</brite> applies: Portage will <e>not</e> check if
251 the package you want to remove is required by another package. It will however
252 warn you when you want to remove an important package that breaks your system
253 if you unmerge it.
254 </p>
255
256 <pre caption="Removing gnumeric from the system">
257 # <i>emerge --unmerge gnumeric</i>
258 </pre>
259
260 <p>
261 When you remove a package from your system, the dependencies of that package
262 that were installed automatically when you installed the software are left. To
263 have Portage locate all dependencies that can now be removed, use
264 <c>emerge</c>'s <c>--depclean</c> functionality. We will talk about this later
265 on.
266 </p>
267
268 </body>
269 </subsection>
270 <subsection>
271 <title>Updating your System</title>
272 <body>
273
274 <p>
275 To keep your system in perfect shape (and not to mention install the latest
276 security updates) you need to update your system regularly. Since Portage only
277 checks the ebuilds in your Portage tree you first have to update your Portage
278 tree. When your Portage tree is updated, you can update your system with
279 <c>emerge --update world</c>. In the next example, we'll also use the
280 <c>--ask</c> switch which will tell Portage to display the list of packages it
281 wants to upgrade and ask you if you want to continue:
282 </p>
283
284 <pre caption="Updating your system">
285 # <i>emerge --update --ask world</i>
286 </pre>
287
288 <p>
289 Portage will then search for newer version of the applications you have
290 installed. However, it will only verify the versions for the applications you
291 have explicitly installed - not the dependencies. If you want to update every
292 single package on your system, add the <c>--deep</c> argument:
293 </p>
294
295 <pre caption="Updating your entire system">
296 # <i>emerge --update --deep world</i>
297 </pre>
298
299 <p>
300 Since security updates also happen in packages you have not explicitly installed
301 on your system (but that are pulled in as dependencies of other programs), it
302 is recommended to run this command once in a while.
303 </p>
304
305 <p>
306 If you have altered any of your <uri link="?part=2&amp;chap=2">USE flags</uri>
307 lately you might want to add <c>--newuse</c> as well. Portage will then verify
308 if the change requires the installation of new packages or recompilation of
309 existing ones:
310 </p>
311
312 <pre caption="Performing a full update">
313 # <i>emerge --update --deep --newuse world</i>
314 </pre>
315
316 </body>
317 </subsection>
318 <subsection>
319 <title>Metapackages</title>
320 <body>
321
322 <p>
323 Some packages in the Portage tree don't have any real content but are used to
324 install a collection of packages. For instance, the <c>kde</c> package will
325 install a complete KDE environment on your system by pulling in various
326 KDE-related packages as dependencies.
327 </p>
328
329 <p>
330 If you ever want to remove such a package from your system, running <c>emerge
331 --unmerge</c> on the package won't have much effect as the dependencies remain
332 on the system.
333 </p>
334
335 <p>
336 Portage has the functionality to remove orphaned dependencies as well, but since
337 the availability of software is dynamically dependent you first need to update
338 your entire system fully, including the new changes you applied when changing
339 USE flags. After this you can run <c>emerge --depclean</c> to remove the
340 orphaned dependencies. When this is done, you need to rebuild the applications
341 that were dynamically linked to the now-removed software titles but don't
342 require them anymore.
343 </p>
344
345 <p>
346 All this is handled with the following three commands:
347 </p>
348
349 <pre caption="Removing orphaned dependencies">
350 # <i>emerge --update --deep --newuse world</i>
351 # <i>emerge --depclean</i>
352 # <i>revdep-rebuild</i>
353 </pre>
354
355 <p>
356 <c>revdep-rebuild</c> is provided by the <c>gentoolkit</c> package; don't forget
357 to emerge it first:
358 </p>
359
360 <pre caption="Installing the gentoolkit package">
361 # <i>emerge gentoolkit</i>
362 </pre>
363
364 </body>
365 </subsection>
366 </section>
367 <section>
368 <title>When Portage is Complaining...</title>
369 <subsection>
370 <title>About SLOTs, Virtuals, Branches, Architectures and Profiles</title>
371 <body>
372
373 <p>
374 As we stated before, Portage is extremely powerful and supports many features
375 that other software management tools lack. To understand this, we explain a few
376 aspects of Portage without going into too much detail.
377 </p>
378
379 <p>
380 With Portage different versions of a single package can coexist on a system.
381 While other distributions tend to name their package to those versions (like
382 <c>freetype</c> and <c>freetype2</c>) Portage uses a technology called
383 <e>SLOT</e>s. An ebuild declares a certain SLOT for its version. Ebuilds with
384 different SLOTs can coexist on the same system. For instance, the
385 <c>freetype</c> package has ebuilds with <c>SLOT="1"</c> and <c>SLOT="2"</c>.
386 </p>
387
388 <p>
389 There are also packages that provide the same functionality but are implemented
390 differently. For instance, <c>metalogd</c>, <c>sysklogd</c> and <c>syslog-ng</c>
391 are all system loggers. Applications that rely on the availability of "a system
392 logger" cannot depend on, for instance, <c>metalogd</c>, as the other system
393 loggers are as good a choice as any. Portage allows for <e>virtuals</e>: each
394 system logger provides <c>virtual/syslog</c> so that applications can depend on
395 <c>virtual/syslog</c>.
396 </p>
397
398 <p>
399 Software in the Portage tree can reside in different branches. By default your
400 system only accepts packages that Gentoo deems stable. Most new software titles,
401 when committed, are added to the testing branch, meaning more testing needs to
402 be done before it is marked as stable. Although you will see the ebuilds for
403 those software in the Portage tree, Portage will not update them before they are
404 placed in the stable branch.
405 </p>
406
407 <p>
408 Some software is only available for a few architectures. Or the software doesn't
409 work on the other architectures, or it needs more testing, or the developer that
410 committed the software to the Portage tree is unable to verify if the package
411 works on different architectures.
412 </p>
413
414 <p>
415 Each Gentoo installation adheres to a certain <c>profile</c> which contains,
416 amongst other information, the list of packages that are required for a system
417 to function normally.
418 </p>
419
420 </body>
421 </subsection>
422 <subsection id="blocked">
423 <title>Blocked Packages</title>
424 <body>
425
426 <pre caption="Portage warning about blocked packages (with --pretend)">
427 [blocks B ] mail-mta/ssmtp (is blocking mail-mta/postfix-2.2.2-r1)
428 </pre>
429
430 <pre caption="Portage warning about blocked packages (without --pretend)">
431 !!! Error: the mail-mta/postfix package conflicts with another package.
432 !!! both can't be installed on the same system together.
433 !!! Please use 'emerge --pretend' to determine blockers.
434 </pre>
435
436 <p>
437 Ebuilds contain specific fields that inform Portage about its dependencies.
438 There are two possible dependencies: build dependencies, declared in
439 <c>DEPEND</c> and run-time dependencies, declared in <c>RDEPEND</c>. When one of
440 these dependencies explicitly marks a package or virtual as being <e>not</e>
441 compatible, it triggers a blockage.
442 </p>
443
444 <p>
445 To fix a blockage, you can choose to not install the package or unmerge the
446 conflicting package first. In the given example, you can opt not to install
447 <c>postfix</c> or to remove <c>ssmtp</c> first.
448 </p>
449
450 <p>
451 It is also possible that two packages that are yet to be installed are blocking
452 each other. In this rare case, you should find out why you need to install both.
453 In most cases you can do with one of the packages alone. If not, please file a
454 bug on <uri link="http://bugs.gentoo.org">Gentoo's bugtracking system</uri>.
455 </p>
456
457 </body>
458 </subsection>
459 <subsection id="masked">
460 <title>Masked Packages</title>
461 <body>
462
463 <pre caption="Portage warning about masked packages">
464 !!! all ebuilds that could satisfy "bootsplash" have been masked.
465 </pre>
466
467 <pre caption="Portage warning about masked packages - reason">
468 !!! possible candidates are:
469
470 - gnome-base/gnome-2.8.0_pre1 (masked by: <i>~x86 keyword</i>)
471 - lm-sensors/lm-sensors-2.8.7 (masked by: <i>-sparc keyword</i>)
472 - sys-libs/glibc-2.3.4.20040808 (masked by: <i>-* keyword</i>)
473 - dev-util/cvsd-1.0.2 (masked by: <i>missing keyword</i>)
474 - media-video/ati-gatos-4.3.0 (masked by: <i>package.mask</i>)
475 - sys-libs/glibc-2.3.2-r11 (masked by: <i>profile</i>)
476 </pre>
477
478 <p>
479 When you want to install a package that isn't available for your system, you
480 will receive this masking error. You should try installing a different
481 application that is available for your system or wait until the package is put
482 available. There is always a reason why a package is masked:
483 </p>
484
485 <ul>
486 <li>
487 <b>~arch keyword</b> means that the application is not tested sufficiently
488 to be put in the stable branch. Wait a few days or weeks and try again.
489 </li>
490 <li>
491 <b>-arch keyword</b> or <b>-* keyword</b> means that the application does
492 not work on your architecture. If you believe the package does work file
493 a bug at our <uri link="http://bugs.gentoo.org">bugzilla</uri> website.
494 </li>
495 <li>
496 <b>missing keyword</b> means that the application has not been tested on
497 your architecture yet. Ask the architecture porting team to test the package
498 or test it for them and report your findings on our <uri
499 link="http://bugs.gentoo.org">bugzilla</uri> website.
500 </li>
501 <li>
502 <b>package.mask</b> means that the package has been found corrupt, unstable
503 or worse and has been deliberately marked as do-not-use.
504 </li>
505 <li>
506 <b>profile</b> means that the package has been found not suitable for your
507 profile. The application might break your system if you installed it or is
508 just not compatible with the profile you use.
509 </li>
510 </ul>
511
512 </body>
513 </subsection>
514 <subsection id="missingdependencies">
515 <title>Missing Dependencies</title>
516 <body>
517
518 <pre caption="Portage warning about missing dependency">
519 emerge: there are no ebuilds to satisfy "&gt;=sys-devel/gcc-3.4.2-r4".
520
521 !!! Problem with ebuild sys-devel/gcc-3.4.2-r2
522 !!! Possibly a DEPEND/*DEPEND problem.
523 </pre>
524
525 <p>
526 The application you are trying to install depends on another package that is not
527 available for your system. Please check <uri
528 link="http://bugs.gentoo.org">bugzilla</uri> if the issue is known and if not,
529 please report it. Unless you are mixing branches this should not occur and is
530 therefore a bug.
531 </p>
532
533 </body>
534 </subsection>
535 <subsection id="ambiguousebuild">
536 <title>Ambiguous Ebuild Name</title>
537 <body>
538
539 <pre caption="Portage warning about ambiguous ebuild names">
540 !!! The short ebuild name "aterm" is ambiguous. Please specify
541 !!! one of the following fully-qualified ebuild names instead:
542
543 dev-libs/aterm
544 x11-terms/aterm
545 </pre>
546
547 <p>
548 The application you want to install has a name that corresponds with more than
549 one package. You need to supply the category name as well. Portage will inform
550 you of possible matches to choose from.
551 </p>
552
553 </body>
554 </subsection>
555 <subsection id="circulardependencies">
556 <title>Circular Dependencies</title>
557 <body>
558
559 <pre caption="Portage warning about circular dependencies">
560 !!! Error: circular dependencies:
561
562 ebuild / net-print/cups-1.1.15-r2 depends on ebuild / app-text/ghostscript-7.05.3-r1
563 ebuild / app-text/ghostscript-7.05.3-r1 depends on ebuild / net-print/cups-1.1.15-r2
564 </pre>
565
566 <p>
567 Two (or more) packages you want to install depend on each other and can
568 therefore not be installed. This is most likely a bug in the Portage tree.
569 Please resync after a while and try again. You can also check <uri
570 link="http://bugs.gentoo.org">bugzilla</uri> if the issue is known and if not,
571 report it.
572 </p>
573
574 </body>
575 </subsection>
576 <subsection id="fetchfailed">
577 <title>Fetch failed</title>
578 <body>
579
580 <pre caption="Portage warning about fetch failed">
581 !!! Fetch failed for sys-libs/ncurses-5.4-r5, continuing...
582 <comment>(...)</comment>
583 !!! Some fetch errors were encountered. Please see above for details.
584 </pre>
585
586 <p>
587 Portage was unable to download the sources for the given application and will
588 try to continue installing the other applications (if applicable). This failure
589 can be due to a mirror that has not synchronised correctly or because the ebuild
590 points to an incorrect location. The server where the sources reside can also be
591 down for some reason.
592 </p>
593
594 <p>
595 Retry after one hour to see if the issue still persists.
596 </p>
597
598 </body>
599 </subsection>
600 <subsection id="profileprotect">
601 <title>System Profile Protection</title>
602 <body>
603
604 <pre caption="Portage warning about profile-protected package">
605 !!! Trying to unmerge package(s) in system profile. 'sys-apps/portage'
606 !!! This could be damaging to your system.
607 </pre>
608
609 <p>
610 You have asked to remove a package that is part of your system's core packages.
611 It is listed in your profile as required and should therefore not be removed
612 from the system.
613 </p>
614
615 </body>
616 </subsection>
617 <subsection id="digesterror">
618 <title>Digest Verification Failures</title>
619 <body>
620
621 <p>
622 Sometimes, when you attempt to emerge a package, it will fail with the message:
623 </p>
624
625 <pre caption="Digest verification failure">
626 &gt;&gt;&gt; checking ebuild checksums
627 !!! Digest verification failed:
628 </pre>
629
630 <p>
631 This is a sign that something is wrong with the Portage tree -- often, it is
632 because a developer may have made a mistake when committing a package to the
633 tree.
634 </p>
635
636 <p>
637 When the digest verification fails, do <e>not</e> try to re-digest the package
638 yourself. Running <c>ebuild foo digest</c> will not fix the problem; it will
639 almost certainly make it worse!
640 </p>
641
642 <p>
643 Instead, wait an hour or two for the tree to settle down. It's likely that the
644 error was noticed right away, but it can take a little time for the fix to
645 trickle down the Portage tree. While you're waiting, check <uri
646 link="http://bugs.gentoo.org">Bugzilla</uri> and see if anyone has reported
647 the problem yet. If not, go ahead and file a bug for the broken package.
648 </p>
649
650 <p>
651 Once you see that the bug has been fixed, you may want to re-sync to pick up
652 the fixed digest.
653 </p>
654
655 <impo>
656 This does <e>not</e> mean that you can re-sync your tree multiple times! As
657 stated in the rsync policy (when you run <c>emerge --sync</c>), users who sync
658 too often will be banned! In fact, it's better to just wait until your next
659 scheduled sync, so that you don't overload the rsync servers.
660 </impo>
661
662 </body>
663 </subsection>
664 </section>
665 </sections>

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