source: x/lib/qtwebengine.xml@ c51bc3f

12.1 12.2 gimp3 ken/TL2024 ken/tuningfonts lazarus plabs/newcss python3.11 rahul/power-profiles-daemon renodr/vulkan-addition trunk xry111/for-12.3 xry111/llvm18 xry111/spidermonkey128
Last change on this file since c51bc3f was c51bc3f, checked in by Pierre Labastie <pierre.labastie@…>, 11 months ago

Fix qtwebengine for python 3.12 and ICU 74.

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1<?xml version="1.0" encoding="ISO-8859-1"?>
2<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3 "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
4 <!ENTITY % general-entities SYSTEM "../../general.ent">
5 %general-entities;
6
7 <!ENTITY qtwebengine-major "5.15">
8<!-- URL if there is a public release
9 <!ENTITY qtwebengine-download-http "https://download.qt.io/archive/qt/&qtwebengine-major;/&qtwebengine-version;/submodules/qtwebengine-everywhere-src-&qtwebengine-version;.tar.xz">
10 URL for a prepared git version -->
11 <!ENTITY qtwebengine-download-http "&sources-anduin-http;/qtwebengine/qtwebengine-&qtwebengine-version;.tar.xz">
12 <!ENTITY qtwebengine-download-ftp " ">
13 <!ENTITY qtwebengine-md5sum "6bb50d47dd854c59d38e67c1ccb6e80d">
14 <!ENTITY qtwebengine-size "307 MB">
15 <!ENTITY qtwebengine-buildsize "5.1 GB (153 MB installed)">
16 <!ENTITY qtwebengine-time "41 SBU (Using parallelism=8)">
17]>
18
19<sect1 id="qtwebengine" xreflabel="qtwebengine-&qtwebengine-version;">
20 <?dbhtml filename="qtwebengine.html"?>
21
22
23 <title>QtWebEngine-&qtwebengine-version;</title>
24
25 <indexterm zone="qtwebengine">
26 <primary sortas="a-qtwebengine">qtwebengine</primary>
27 </indexterm>
28
29 <sect2 role="package">
30 <title>Introduction to QtWebEngine</title>
31
32 <para>
33 <application>QtWebEngine</application> integrates
34 <application>chromium</application>'s web capabilities into Qt. It
35 ships with its own copy of ninja which it uses for the build if it cannot
36 find a system copy, and various copies of libraries from ffmpeg, icu,
37 libvpx, and zlib (including libminizip) which have been forked by the
38 <application>chromium</application> developers.
39 </para>
40
41 <para>
42 This package and browsers using it may be useful if you need to use a
43 website designed for google chrome, or chromium, browsers.
44 </para>
45
46 <important>
47 <para>
48 Qt-5.15 reached End Of Life on 26 May 2023. Extended lifetime Qt5.15 LTS
49 has been extended until 26th May 2025 for those with subscription licenses.
50 Because qtwebengine uses chromium code under the LGPL, it appears that any
51 new backported CVE fixes for QtWebEngine will be available after Qt makes
52 public releases of its current versions.
53 </para>
54 </important>
55
56 <warning>
57 <para>
58 QtWebEngine uses a forked copy of chromium, and is therefore vulnerable
59 to many issues found there. The Qt developers have always preferred to
60 make releases at the same time as the rest of Qt (rather than adding
61 emergency fixes), but with stable versions getting released after the
62 current development version. Now that they are keen to move to Qt6, the
63 5.15.3 and later Qt-5.15 releases are initially only available to paying
64 customers. QtWebEngine is something of an exception because of its LGPL
65 licence, but getting the git sources (with the forked chromium submodule)
66 to a position where they will successfully build on a current BLFS system
67 can take a lot of effort and therefore updates to the book may be delayed.
68 </para>
69
70 <para>
71 It seems likely that future 5.15-series versions will also be released
72 long after the chromium vulnerabilities are known, but fixes for
73 QtWebEngine can be found in git and the editors take the view that
74 known vulnerabilities in browsers should be fixed.
75 </para>
76
77 <para> <!-- for git versions -->
78 The tarball linked to below was created from the 5.15<!--.15--> git branch
79 and the 87-branch of the chromium submodule (which is forked from
80 chromium). See the GIT-VERSIONS file in the tarball for details of the
81 latest commits.
82 </para>
83 </warning>
84
85 <!-- note for editors on obtaining webengine from git.
86 First (if you do not already have a past version)
87 git clone git://code.qt.io/qt/qtwebengine.git
88 git submodule init -
89 that will report qtwebengine-chromium.git registered for src/3rdparty
90 now find the main branch names:
91 git fetch origin
92 git branch -r
93 after a release is prepared (even if the rest is not public), the 5.15
94 branch now seems to get updated and might be what you want. But in the
95 approach to 5.15.6 the backported CVE and other security fixes were only
96 applied to 5.15.6. So, assuming that a 5.15.7 branch now exists,
97 git checkout origin/5.15.7
98 Confirm that HEAD is where you expected.
99 Now go to src/3rdparty
100 git fetch origin
101 git branch -r
102 The required branch is likely to be 87-branch unless there is a newer one
103 mentioned in the 5.15 cgit web page (below).
104 git checkout origin/87-branch (or whatever)
105 Use git log or git tk to look at its HEAD and check it seems appropriate.
106 If this doesn't work, use 'git submodule update'
107
108 To decide when it might be worth creating a new tarball, periodically keep
109 an eye on https://code.qt.io/cgit/qt/qtwebengine.git/ (currently, the 5.15.6
110 branch, 5.15.7 might get used later). The interesting items are CVE fixes
111 for known chromium vulnerabilities, as well as numbered Security bugs -
112 again, these relate to chromium.
113
114 When I noticed some updates in late March I was searching for one of the
115 CVEs mentioned, and google found a link to a review page for Michael Brüning
116 at https://codereview.qt.nokia.com/q/owner:michael.bruning%2540qt.io. At that
117 time I could see various unmerged items, so I waited. The items for the
118 90-based chromium module are not relevant to 5.15-series (possibly they will
119 be for qtwebengine-6+). Review queues for other Qt employees might be found
120 in a similar way, but remember that everythng EXCEPT qtwebengine and chromium
121 is private to Qt until they choose to release it.
122
123 NOTE: the 3rdparty/chromium tree may contain more patches than have been
124 merged into the current 5.15.x branch. Any patches after what was in the
125 last 'update chromium' merge in qtwebengine occasionally break the build.
126
127 After merging the contents of the qtwebengine and src/3rdparty git extracts,
128 in the top level please create a GIT-VERSIONS file summarising the HEAD
129 commits of both parts, as a reminder of where we are up to. I've nove added
130 a CVE-fixes to keep track of what has been fixed (comits before 5.15.2 did not
131 mention the CVEs until they were detailed in a release).
132
133 Now create tarballs - 'git archive' does not work across submodule boundaries,
134 so you need to create one archive from the top of qtwebengine/ and another
135 from the top of src/3rdparty (chromium, gn, ninja are apparently all part of
136 the qtwebengine-chromium module). Then in a work area untar the qtwebengine
137 tarball, go down to src/3rdparty and untar the submodule tarball.
138 Decide on what to call the result and create a full xz tarball using tar -cJf.
139
140 NOTE: To use git archive, use something like this:
141 git archive - -format tar.gz - -output qtwebengine.tar.gz HEAD
142 git archive - -format tar.gz - -output chromium.tar.gz HEAD
143
144 UPDATE: Since we have to host the tarball, and it is over 300MB, it makes
145 sense to create a patch for subsequent fixes (for the first version, 314KB
146 including the updates to the GIT-VERSIONS file). For future updates, view
147 the current updates patch to see the previous commits. When the new commits
148 have been applied, rename the updated version to 'b', but untar the
149 unpatched tarball as 'a' and then diff a to b in the usual manner to get
150 all updates since the tarball was created.
151
152 For our own releases, probably best to create a fresh tarball.
153
154 end of note for editors -->
155
156 &lfs120_checked;
157
158 <warning>
159 <para>
160 By default, ninja will use all online CPUs +2 (if at least 4 exist),
161 even if they are not available to the current task because the build
162 terminal has been restricted with 'taskset'. In BLFS, this package
163 takes more time to build than any other. In one example,
164 the build of this package crashed at about the 90 percent point
165 due to an out of memory problem on a system with 24 cores and 32 GB
166 of memory.
167 </para>
168
169 <para>
170 To work around this, see the Command Explanations below.
171 </para>
172 </warning>
173
174 <note>
175 <para>
176 If you are upgrading and have installed a newer version of <xref
177 linkend='icu'/> since you last installed <xref linkend='qt5'/>, you
178 will need to reinstall Qt5 before upgrading, otherwise the final link
179 of this package will fail with a warning that the version of icu
180 libraries needed by libQt5Core.so may conflict with the version
181 used for this package.
182 </para>
183
184 <para>
185 Unusually, the shipped GN build system (used to create the Ninja files)
186 requires a static <filename class="libraryfile">libstdc++.a</filename>
187 although the installed libraries correctly use the shared version. If
188 that static library is not present, the build will fail quite quickly.
189 Please note that if you try to build webengine as part of
190 <application>Qt</application> and the static library is not available,
191 that build will either complete without installing webengine, or else
192 fail during the install (both variants were observed in 5.12.0).
193 </para>
194 </note>
195
196 <bridgehead renderas="sect3">Package Information</bridgehead>
197 <itemizedlist spacing="compact">
198 <listitem>
199 <para>
200 Download (HTTP): <ulink url="&qtwebengine-download-http;"/>
201 </para>
202 </listitem>
203 <listitem>
204 <para>
205 Download (FTP): <ulink url="&qtwebengine-download-ftp;"/>
206 </para>
207 </listitem>
208 <listitem>
209 <para>
210 Download MD5 sum: &qtwebengine-md5sum;
211 </para>
212 </listitem>
213 <listitem>
214 <para>
215 Download size: &qtwebengine-size;
216 </para>
217 </listitem>
218 <listitem>
219 <para>
220 Estimated disk space required: &qtwebengine-buildsize;
221 </para>
222 </listitem>
223 <listitem>
224 <para>
225 Estimated build time: &qtwebengine-time;
226 </para>
227 </listitem>
228 </itemizedlist>
229
230 <bridgehead renderas="sect3">Additional Downloads</bridgehead>
231 <itemizedlist spacing="compact">
232 <!--<listitem>
233 <para>
234 Required patch:
235 <!\-\- keep links for releases and git versions as a reminder
236 that the tarball names names differ
237 <ulink url="&patch-root;/qtwebengine-everywhere-src-&qtwebengine-version;-ICU68-2.patch"/> \-\->
238
239 <ulink url="&patch-root;/qtwebengine-&qtwebengine-version;-5.15.7-1.patch"/>
240 </para>
241 </listitem>-->
242 <listitem>
243 <para>
244 Required patch:
245 <ulink url="&patch-root;/qtwebengine-&qtwebengine-version;-build_fixes-1.patch"/>
246 </para>
247 </listitem>
248 <listitem>
249 <para>
250 Required patch:
251 <ulink url="&patch-root;/qtwebengine-&qtwebengine-version;-ffmpeg5_fixes-1.patch"/>
252 </para>
253 </listitem>
254 <!--
255 <listitem>
256 <para>
257 Required patch:
258 <ulink url="&patch-root;/qtwebengine-&qtwebengine-version;-icu_73-1.patch"/>
259 </para>
260 </listitem>
261 -->
262 </itemizedlist>
263
264 <bridgehead renderas="sect3">qtwebengine Dependencies</bridgehead>
265
266 <bridgehead renderas="sect4">Required</bridgehead>
267 <!-- the qmake output tends to be misleading. 'khr' is from Mesa -->
268 <para role="required">
269 <xref linkend="nodejs"/>,
270 <xref linkend="nss"/>,
271 <xref linkend="pciutils"/>, and
272 (<xref linkend='qt5'/> or
273 <xref role="nodep" linkend='qt5-components'/> with qtlocation and qtwebchannel)
274 </para>
275
276 <bridgehead renderas="sect4">Recommended</bridgehead>
277 <note>
278 <para>
279 If these packages are not installed, the build process will compile and
280 install its own (perhaps older) version, with the side effect of
281 increasing build and installed disk space and build time.
282 </para>
283 </note>
284
285 <para role="recommended">
286 either <xref linkend="alsa-lib"/> or
287 <xref linkend="pulseaudio"/> (or both),
288 <xref linkend="ffmpeg"/>,
289 <!-- awkward wording - libxslt needs libxml2, if libxml2 is built
290 before icu then the *shipped* icu will be used -->
291 <xref linkend="icu"/> (built before <xref linkend="libxml2"/>) ,
292 <xref linkend="libwebp"/>,
293 <xref linkend="libxslt"/>, and
294 <xref linkend="opus"/>
295 </para>
296
297 <bridgehead renderas="sect4">Optional</bridgehead>
298 <para role="optional">
299 <xref linkend="libevent"/>,
300 <xref linkend="mitkrb"/>,
301 <xref linkend="pipewire"/>,
302 <xref linkend="poppler"/>,
303 <ulink url="https://github.com/open-source-parsers/jsoncpp/releases">jsoncpp</ulink>,
304 <ulink url="https://github.com/cisco/libsrtp/releases">libsrtp</ulink>,
305 <ulink url="https://google.github.io/snappy/">snappy</ulink>
306 </para>
307
308 <para condition="html" role="usernotes">
309 Editor Notes: <ulink url="&blfs-wiki;/qtwebengine"/>
310 </para>
311 </sect2>
312
313 <sect2 role="installation">
314 <title>Installation of qtwebengine</title>
315
316<!-- following merely commented instead of deleted, in case we need to
317 drop back when a future version of python3 is released -->
318<!--<note>
319 <para>
320 Unlike version 5.15.2, the chromium-derived build system now needs
321 <command>python</command> to be available and to be python2. In
322 BLFS-10.1 the creation of the python symlink was removed as a step
323 towards eventually getting rid of python2 (other old packages which
324 need python2 usually work by invoking python2). If you are still
325 using an earlier version of BLFS where
326 <filename>/usr/bin/python</filename> exists, you can skip the
327 commands to create the symlink, and to later remove it.
328 </para>
329 </note>
330
331 <para>
332 First, as the <systemitem class="username">root</systemitem>
333 user, create the python symlink:
334 </para>
335
336<screen role="root"><userinput>ln -svf /usr/bin/python{2,}</userinput></screen>-->
337
338
339<!--<para>
340 Now apply a patch to update from 5.15.6 to the security and other fixes
341 contained in the 5.15.7 source:
342 </para>
343
344<screen><userinput remap="pre">patch -Np1 -i ../qtwebengine-&qtwebengine-version;-5.15.7-1.patch</userinput></screen>-->
345
346 <para>
347 Apply a patch to fix several issues that can prevent the build from completing,
348 and to force it to use python3:
349 </para>
350
351<screen><userinput remap="pre">patch -Np1 -i ../qtwebengine-&qtwebengine-version;-build_fixes-1.patch</userinput></screen>
352
353 <para>
354 If building with system <xref linkend='ffmpeg'/> as the editors
355 recommand, apply a patch that resolves problems when building with
356 ffmpeg-5 and later:
357 </para>
358
359<screen><userinput remap="pre">patch -Np1 -i ../qtwebengine-&qtwebengine-version;-ffmpeg5_fixes-1.patch</userinput></screen>
360
361 <!-- The ffmpeg commit effadce6c756247ea8bae32dc13bb3e6f464f0eb
362 already in system ffmpeg, but not this old shipped copy.
363 Not marked nodump because it won't affect the build with system
364 ffmpeg anyway. -->
365 <para>
366 Otherwise, fix an issue in shipped ffmpeg causing it fail to build
367 with Binutils 2.41 or later:
368 </para>
369
370<screen><userinput remap="pre">sed 's/(uint8_t)\(([^)]*)\|shift\)/\1 \&amp; 0x1F/' \
371 -i src/3rdparty/chromium/third_party/ffmpeg/libavcodec/x86/mathops.h</userinput></screen>
372
373<!-- start of commands for git versions only -->
374 <para>
375 Although the build_fixes patch has ensured that git is not invoked during the build,
376 the build system has labyrinthine rules of byzantine complexity, and in
377 particular trying to build without two <filename>.git</filename> directories
378 will lead to it eventually falling into unexpected and unbuildable code
379 which references a private header that has not been created. Avoid this
380 by creating the required directories:
381 </para>
382
383<screen><userinput>mkdir -pv .git src/3rdparty/chromium/.git</userinput></screen>
384
385 <para>
386 Because this version of qtwebengine is aimed at a later release than the
387 current public releases, change it to build for qt-&qt5-version; using a
388 sed:
389 </para>
390
391<screen><userinput>sed -e '/^MODULE_VERSION/s/5.*/&qt5-version;/' -i .qmake.conf</userinput></screen>
392<!-- end of commands for git versions only -->
393
394 <para>
395 Now, ensure that the local headers are available when not building as
396 part of the complete <xref linkend="qt5"/>:
397 </para>
398
399<screen><userinput>find -type f -name "*.pr[io]" |
400 xargs sed -i -e 's|INCLUDEPATH += |&amp;$$QTWEBENGINE_ROOT/include |'</userinput></screen>
401
402 <para>
403 Next, allow the pulseaudio library to be linked at build time, instead
404 of run time. This also prevents an issue with newer pulseaudio:
405 </para>
406
407<screen><userinput>sed -e '/link_pulseaudio/s/false/true/' \
408 -i src/3rdparty/chromium/media/media_options.gni</userinput></screen>
409
410 <para>
411 Next, fix the build tools so they can be run with Python-3.11+:
412 </para>
413
414<screen><userinput>sed -e 's/\^(?i)/(?i)^/' \
415 -i src/3rdparty/chromium/tools/metrics/ukm/ukm_model.py &amp;&amp;
416sed -e "s/'rU'/'r'/" \
417 -i src/3rdparty/chromium/tools/grit/grit/util.py</userinput></screen>
418
419 <para>
420 Several fixes are needed for using Python-3.12+: first, either remove
421 references to the removed <command>imp</command> module or
422 replace it with the newer <command>importlib</command> module:
423 </para>
424
425<screen><userinput>sed -e "/import imp/d" \
426 -i src/3rdparty/chromium/mojo/public/tools/mojom/mojom/fileutil.py \
427 src/3rdparty/chromium/mojo/public/tools/mojom/mojom/parse/lexer.py &amp;&amp;
428sed -e "s/import imp/import importlib.util/" \
429 -e 's@.*load_source.*@\
430 spec = importlib.util.spec_from_file_location(fullname, filepath)\
431 mod = importlib.util.module_from_spec(spec);\
432 spec.loader.exec_module(mod)\
433 return mod@' \
434 -i src/3rdparty/chromium/components/resources/protobufs/binary_proto_generator.py</userinput></screen>
435
436 <para>
437 Remove an obsolete instance of and a reference to the
438 <command>six</command> module:
439 </para>
440
441<screen><userinput>sed -e /six.move/d \
442 -i src/3rdparty/chromium/third_party/protobuf/python/google/protobuf/internal/python_message.py &amp;&amp;
443 rm -r src/3rdparty/chromium/tools/grit/third_party/six</userinput></screen>
444
445 <para>
446 There is also a workaround needed for ICU-74+:
447 </para>
448
449<screen><userinput>sed -e 's/^#define BA_LB_COUNT.*$/#define BA_LB_COUNT 40/' \
450-i src/3rdparty/chromium/third_party/blink/renderer/platform/text/text_break_iterator.cc</userinput></screen>
451
452 <para>
453 Finally, fix a change in the build system which allows its developers to
454 pass e.g. -j20 to make (for quick tests of some areas) but breaks the
455 build with LFS's use of the NINJAJOBS environment variable:
456 </para>
457
458<!-- editors: See thread at
459http://lists.linuxfromscratch.org/pipermail/blfs-dev/2019-December/036996.html
460et.seq, particularly 037002.html which shows the commit near the end. -->
461
462<screen><userinput>sed -i 's/NINJAJOBS/NINJA_JOBS/' src/core/gn_run.pro</userinput></screen>
463
464<!-- now that we always install this as 5.15.2, this seems to be redundant
465 <para>
466 If an older version of the package's main library has been installed,
467 when the package is built separately it will link to that in preference
468 to its own not-yet-installed version, and fail because of missing symbols.
469 Prevent that by, as the <systemitem class="username">root</systemitem>
470 user, moving the symlink out of the way:
471 </para>
472
473<screen role="root"><userinput>if [ -e ${QT5DIR}/lib/libQt5WebEngineCore.so ]; then
474 mv -v ${QT5DIR}/lib/libQt5WebEngineCore.so{,.old}
475fi</userinput></screen>-->
476
477<!--<para>
478 The last fix is needed to build with gcc-12:
479 </para>
480
481<screen><userinput>sed -e '/#include/i#include &lt;vector&gt;' \
482 -i src/3rdparty/chromium/third_party/skia/src/utils/SkParseColor.cpp</userinput></screen>-->
483
484 <para>
485 Install <application>qtwebengine</application> by running the following
486 commands:
487 </para>
488
489<screen><userinput>mkdir build &amp;&amp;
490cd build &amp;&amp;
491qmake .. -- -system-ffmpeg -proprietary-codecs -webengine-icu &amp;&amp;
492make</userinput></screen>
493
494<!--
495 <para>
496 if you wish to build the HTML documentation, issue:
497 </para>
498
499<screen><userinput>make docs</userinput></screen>
500-->
501 <para>
502 This package does not come with a test suite.
503 </para>
504
505 <para>
506 Now, as the <systemitem class="username">root</systemitem> user:
507 </para>
508
509<screen role="root"><userinput>make install</userinput></screen>
510
511 <!-- EDITORS NOTE: If you are updating this package, use INSTALL_ROOT=
512 instead of DESTDIR= -->
513<!--
514 <para>
515 If you built the HTML documentation, install it with:
516 </para>
517
518<screen role="root"><userinput>make install_docs</userinput></screen>
519-->
520 <para>
521 Remove references to the build directory from installed library
522 dependency (prl) files by running the following
523 commands as the <systemitem class="username">root</systemitem> user:
524 </para>
525
526<screen role="root"><userinput>find $QT5DIR/ -name \*.prl \
527 -exec sed -i -e '/^QMAKE_PRL_BUILD_DIR/d' {} \;</userinput></screen>
528
529<!--<para>
530 Finally, as the <systemitem class="username">root</systemitem>
531 user, remove the python symlink:
532 </para>
533
534<screen role="root"><userinput>rm -v /usr/bin/python</userinput></screen>-->
535 </sect2>
536
537 <sect2 role="commands">
538 <title>Command Explanations</title>
539
540 <para>
541 <command>qmake</command>: This will build the included copy of
542 <application>ninja</application> if it is not already installed
543 and use it to configure the build.
544 </para>
545
546 <para>
547 <command>-- -system-ffmpeg -proprietary-codecs -webengine-icu</command>: If
548 any options are passed to qmake they must come after '--' which must follow
549 '..' that points to the main directory. The options here cause it to use
550 system ffmpeg and system icu. The '-proprietary-codecs' option allows
551 ffmpeg to decode H264 and H265 codecs. If built as part of full Qt5, the
552 system icu is automatically used (only) by Qt5Core if it is available, but
553 unless this option is used webengine will always use its shipped copy of icu,
554 adding time and space to the build. Remove the
555 <parameter>-system-ffmpeg</parameter> switch if you don't have
556 <xref linkend='ffmpeg'/> installed and want to build this package
557 with an internal copy of ffmpeg.
558 </para>
559
560 <para>
561 <option>-webengine-jumbo-build 0</option>: If this is added to the qmake
562 command it will cause the 'Jumbo Build Merge Limit' to be reported as 'no'
563 instead of 8. That turns off the jumbo build. Some distros do that to get
564 a smaller build on some architectures such as MIPS. On x86_64 it might save
565 a little space in the build, but the build time will increase by a very
566 large amount.
567 </para>
568
569 <para>
570 <option>-webengine-kerberos</option>: Add this if you have installed <xref
571 linkend="mitkrb"/> and wish to connect from a browser using QtWebEngine
572 to a webserver which requires you to connect via kerberos.
573 </para>
574
575 <!--
576 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
577 href="../../xincludes/SIOCGSTAMP.xml"/>
578 -->
579
580 <para>
581 <option>NINJAJOBS=4 make</option>: If you patched system ninja in LFS to
582 recognize the NINJAJOBS environment variable, this command will run system
583 ninja with the specified number of jobs (i.e. 4).
584 There are several reasons why you might want to use options like this this:
585 </para>
586
587 <itemizedlist>
588 <listitem>
589 <para>
590 Building on a subset of CPUs allows measuring the build time
591 for a smaller number of processors, and/or running other
592 CPU-intensive tasks at the same time. For an editor on a machine
593 with a lot of CPUs, trying to measure the build time for a 4-CPU
594 machine, <option>NINJAJOBS=4 make</option> will give a reasonable
595 approximation (there is a short period where N+2 python and node
596 jobs run).
597 </para>
598 </listitem>
599 <listitem>
600 <para>
601 On a machine with only 4 CPUs online, the default of scheduling
602 N+2 jobs for qtwebengine is slower by between 3% and 7%, probably
603 because of the size of the C++ files and their many includes and
604 templates. Therefore, if in doubt set NINJAJOBS to the number of CPUs.
605 </para>
606 </listitem>
607 <listitem>
608 <para>
609 Reducing the number of cores being used on long running, CPU
610 intensive packages may alleviate heat problems.
611 </para>
612 </listitem>
613 <listitem>
614 <para>
615 Reducing the number of cores will prevent potential out-of-memory
616 problems on systems that do not have enough memory (or swap)
617 when all cores are active. A suggested approach is to limit
618 the number of cores to about one core for each 1.5 GB of
619 combined RAM and swap space.
620 </para>
621 </listitem>
622 </itemizedlist>
623
624 </sect2>
625
626 <sect2 role="configuration">
627 <title>Configuring QtWebEngine</title>
628
629 <sect3 id="qtwebengine-config">
630 <title>Configuration Information</title>
631
632 <para>
633 If you are upgrading from an older minor version of this
634 application, for some webpages to load you may need to
635 clear the <emphasis>browser</emphasis> caches, e.g. for
636 <application>falkon</application> they will be found in
637 <filename class="directory">~/.cache/falkon/</filename>.
638 You will need to do this if the browser starts to render
639 the page and then changes to a blank tab with a message
640 that something went wrong, and a button to Retry. Even
641 after removing the old caches, you may need to retry a
642 few times for each affected tab.
643 </para>
644
645 <para>
646 If a browser using this package fails to run and when run
647 from a term it reports 'Trace/breakpoint trap' that is
648 probably a kernel configuration issue - there is no need
649 to rebuild QtWebEngine, see the next section, recompile
650 the kernel and reboot to the new kernel.
651 </para>
652
653 </sect3>
654
655 </sect2>
656
657 <sect2 role="kernel" id="qtwebengine-kernel">
658 <title>Kernel Configuration</title>
659
660 <para>
661 This package does not require any of the optional kernel namespace items,
662 but if User namespace is enabled <phrase revision="systemd">(as happens
663 in some unit files, for hardening)</phrase> PID namespace must also be
664 enabled. In that case enable the following options in the kernel
665 configuration and recompile the kernel if necessary:
666 </para>
667
668 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
669 href="qtwebengine-kernel.xml"/>
670
671 <indexterm zone="qtwebengine qtwebengine-kernel">
672 <primary sortas="d-qtwebengine">qtwebengine</primary>
673 </indexterm>
674 </sect2>
675
676 <sect2 role="content">
677 <title>Contents</title>
678
679 <segmentedlist>
680 <segtitle>Installed Programs</segtitle>
681 <segtitle>Installed Libraries</segtitle>
682 <segtitle>Installed Directories</segtitle>
683
684 <seglistitem>
685 <seg>
686 qtwebengine_convert_dict and
687 QtWebEngineProcess (in $QT5DIR/libexec)
688 </seg>
689 <seg>
690 libQt5Pdf.so,
691 libQt5PdfWidgets.so,
692 libQt5WebEngineCore.so,
693 libQt5WebEngine.so, and
694 libQt5WebEngineWidgets.so
695 </seg>
696 <seg>
697 $QT5DIR/include/QtPdf,
698 $QT5DIR/include/QtPdfWidgets,
699 $QT5DIR/include/QtWebEngine,
700 $QT5DIR/include/QtWebEngineCore,
701 $QT5DIR/include/QtWebEngineWidgets,
702 $QT5DIR/qml/QtWebEngine, and
703 $QT5DIR/translations/qtwebengine_locales
704 </seg>
705 </seglistitem>
706 </segmentedlist>
707
708 <variablelist>
709 <bridgehead renderas="sect3">Short Descriptions</bridgehead>
710 <?dbfo list-presentation="list"?>
711 <?dbhtml list-presentation="table"?>
712
713 <varlistentry id="qtwebengine_convert_dict">
714 <term><command>qtwebengine_convert_dict</command></term>
715 <listitem>
716 <para>
717 converts hunspell dictionaries (<literal>.dic</literal>) to chromium
718 format (<literal>.bdic</literal>)
719 </para>
720 <indexterm zone="qtwebengine qtwebengine_convert_dict">
721 <primary sortas="b-qtwebengine_convert_dict">qtwebengine_convert_dict</primary>
722 </indexterm>
723 </listitem>
724 </varlistentry>
725
726 <varlistentry id="QtWebEngineProcess">
727 <term><command>QtWebEngineProcess</command></term>
728 <listitem>
729 <para>
730 is a libexec program which runs a zygote process (one that listens
731 for spawn requests from a master process and will fork itself in
732 response)
733 </para>
734 <indexterm zone="qtwebengine QtWebEngineProcess">
735 <primary sortas="b-QtWebEngineProcess">QtWebEngineProcess</primary>
736 </indexterm>
737 </listitem>
738 </varlistentry>
739
740 <varlistentry id="libQtWebEngine-lib">
741 <term><filename class="libraryfile">libQtWebEngine.so</filename></term>
742 <listitem>
743 <para>
744 provides QML types for rendering web content within a QML application
745 </para>
746 <indexterm zone="qtwebengine libQtWebEngine-lib">
747 <primary sortas="c-libQtWebEngine">libQtWebEngine.so</primary>
748 </indexterm>
749 </listitem>
750 </varlistentry>
751
752 <varlistentry id="libQtWebEngineCore">
753 <term><filename class="libraryfile">libQtWebEngineCore.so</filename></term>
754 <listitem>
755 <para>
756 provides public API shared by both QtWebEngine and QtWebEngineWidgets
757 </para>
758 <indexterm zone="qtwebengine libQtWebEngineCore">
759 <primary sortas="c-libQtWebEngineCore">libQtWebEngineCore.so</primary>
760 </indexterm>
761 </listitem>
762 </varlistentry>
763
764 <varlistentry id="libQtWebEngineWidgets">
765 <term><filename class="libraryfile">libQtWebEngineWidgets.so</filename></term>
766 <listitem>
767 <para>
768 provides a web browser engine as well as C++ classes to render and
769 interact with web content
770 </para>
771 <indexterm zone="qtwebengine libQtWebEngineWidgets">
772 <primary sortas="c-libQtWebEngineWidgets">libQtWebEngineWidgets.so</primary>
773 </indexterm>
774 </listitem>
775 </varlistentry>
776
777 </variablelist>
778 </sect2>
779
780</sect1>
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