1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
|
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-package-notes">
<title>Package Notes</title>
<para>This chapter contains information about how to use and maintain
the Nix expressions for a number of specific packages, such as the
Linux kernel or X.org.</para>
<!--============================================================-->
<section xml:id="sec-linux-kernel">
<title>Linux kernel</title>
<para>The Nix expressions to build the Linux kernel are in <link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/os-specific/linux/kernel"><filename>pkgs/os-specific/linux/kernel</filename></link>.</para>
<para>The function that builds the kernel has an argument
<varname>kernelPatches</varname> which should be a list of
<literal>{name, patch, extraConfig}</literal> attribute sets, where
<varname>name</varname> is the name of the patch (which is included in
the kernel’s <varname>meta.description</varname> attribute),
<varname>patch</varname> is the patch itself (possibly compressed),
and <varname>extraConfig</varname> (optional) is a string specifying
extra options to be concatenated to the kernel configuration file
(<filename>.config</filename>).</para>
<para>The kernel derivation exports an attribute
<varname>features</varname> specifying whether optional functionality
is or isn’t enabled. This is used in NixOS to implement
kernel-specific behaviour. For instance, if the kernel has the
<varname>iwlwifi</varname> feature (i.e. has built-in support for
Intel wireless chipsets), then NixOS doesn’t have to build the
external <varname>iwlwifi</varname> package:
<programlisting>
modulesTree = [kernel]
++ pkgs.lib.optional (!kernel.features ? iwlwifi) kernelPackages.iwlwifi
++ ...;
</programlisting>
</para>
<para>How to add a new (major) version of the Linux kernel to Nixpkgs:
<orderedlist>
<listitem>
<para>Copy the old Nix expression
(e.g. <filename>linux-2.6.21.nix</filename>) to the new one
(e.g. <filename>linux-2.6.22.nix</filename>) and update it.</para>
</listitem>
<listitem>
<para>Add the new kernel to <filename>all-packages.nix</filename>
(e.g., create an attribute
<varname>kernel_2_6_22</varname>).</para>
</listitem>
<listitem>
<para>Now we’re going to update the kernel configuration. First
unpack the kernel. Then for each supported platform
(<literal>i686</literal>, <literal>x86_64</literal>,
<literal>uml</literal>) do the following:
<orderedlist>
<listitem>
<para>Make an copy from the old
config (e.g. <filename>config-2.6.21-i686-smp</filename>) to
the new one
(e.g. <filename>config-2.6.22-i686-smp</filename>).</para>
</listitem>
<listitem>
<para>Copy the config file for this platform
(e.g. <filename>config-2.6.22-i686-smp</filename>) to
<filename>.config</filename> in the kernel source tree.
</para>
</listitem>
<listitem>
<para>Run <literal>make oldconfig
ARCH=<replaceable>{i386,x86_64,um}</replaceable></literal>
and answer all questions. (For the uml configuration, also
add <literal>SHELL=bash</literal>.) Make sure to keep the
configuration consistent between platforms (i.e. don’t
enable some feature on <literal>i686</literal> and disable
it on <literal>x86_64</literal>).
</para>
</listitem>
<listitem>
<para>If needed you can also run <literal>make
menuconfig</literal>:
<screen>
$ nix-env -i ncurses
$ export NIX_CFLAGS_LINK=-lncurses
$ make menuconfig ARCH=<replaceable>arch</replaceable></screen>
</para>
</listitem>
<listitem>
<para>Copy <filename>.config</filename> over the new config
file (e.g. <filename>config-2.6.22-i686-smp</filename>).</para>
</listitem>
</orderedlist>
</para>
</listitem>
<listitem>
<para>Test building the kernel: <literal>nix-build -A
kernel_2_6_22</literal>. If it compiles, ship it! For extra
credit, try booting NixOS with it.</para>
</listitem>
<listitem>
<para>It may be that the new kernel requires updating the external
kernel modules and kernel-dependent packages listed in the
<varname>linuxPackagesFor</varname> function in
<filename>all-packages.nix</filename> (such as the NVIDIA drivers,
AUFS, etc.). If the updated packages aren’t backwards compatible
with older kernels, you may need to keep the older versions
around.</para>
</listitem>
</orderedlist>
</para>
</section>
<!--============================================================-->
<section xml:id="sec-xorg">
<title>X.org</title>
<para>The Nix expressions for the X.org packages reside in
<filename>pkgs/servers/x11/xorg/default.nix</filename>. This file is
automatically generated from lists of tarballs in an X.org release.
As such it should not be modified directly; rather, you should modify
the lists, the generator script or the file
<filename>pkgs/servers/x11/xorg/overrides.nix</filename>, in which you
can override or add to the derivations produced by the
generator.</para>
<para>The generator is invoked as follows:
<screen>
$ cd pkgs/servers/x11/xorg
$ cat tarballs-7.5.list extra.list old.list \
| perl ./generate-expr-from-tarballs.pl
</screen>
For each of the tarballs in the <filename>.list</filename> files, the
script downloads it, unpacks it, and searches its
<filename>configure.ac</filename> and <filename>*.pc.in</filename>
files for dependencies. This information is used to generate
<filename>default.nix</filename>. The generator caches downloaded
tarballs between runs. Pay close attention to the <literal>NOT FOUND:
<replaceable>name</replaceable></literal> messages at the end of the
run, since they may indicate missing dependencies. (Some might be
optional dependencies, however.)</para>
<para>A file like <filename>tarballs-7.5.list</filename> contains all
tarballs in a X.org release. It can be generated like this:
<screen>
$ export i="mirror://xorg/X11R7.4/src/everything/"
$ cat $(PRINT_PATH=1 nix-prefetch-url $i | tail -n 1) \
| perl -e 'while (<>) { if (/(href|HREF)="([^"]*.bz2)"/) { print "$ENV{'i'}$2\n"; }; }' \
| sort > tarballs-7.4.list
</screen>
<filename>extra.list</filename> contains libraries that aren’t part of
X.org proper, but are closely related to it, such as
<literal>libxcb</literal>. <filename>old.list</filename> contains
some packages that were removed from X.org, but are still needed by
some people or by other packages (such as
<varname>imake</varname>).</para>
<para>If the expression for a package requires derivation attributes
that the generator cannot figure out automatically (say,
<varname>patches</varname> or a <varname>postInstall</varname> hook),
you should modify
<filename>pkgs/servers/x11/xorg/overrides.nix</filename>.</para>
</section>
<!--============================================================-->
<!--
<section>
<title>Gnome</title>
<para>* Expression is auto-generated</para>
<para>* How to update</para>
</section>
-->
<!--============================================================-->
<!--
<section>
<title>GCC</title>
<para>…</para>
</section>
-->
<!--============================================================-->
<section xml:id="sec-eclipse">
<title>Eclipse</title>
<para>
The Nix expressions related to the Eclipse platform and IDE are in
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/editors/eclipse"><filename>pkgs/applications/editors/eclipse</filename></link>.
</para>
<para>
Nixpkgs provides a number of packages that will install Eclipse in
its various forms, these range from the bare-bones Eclipse
Platform to the more fully featured Eclipse SDK or Scala-IDE
packages and multiple version are often available. It is possible
to list available Eclipse packages by issuing the command:
<screen>
$ nix-env -f '<nixpkgs>' -qaP -A eclipses --description
</screen>
Once an Eclipse variant is installed it can be run using the
<command>eclipse</command> command, as expected. From within
Eclipse it is then possible to install plugins in the usual manner
by either manually specifying an Eclipse update site or by
installing the Marketplace Client plugin and using it to discover
and install other plugins. This installation method provides an
Eclipse installation that closely resemble a manually installed
Eclipse.
</para>
<para>
If you prefer to install plugins in a more declarative manner then
Nixpkgs also offer a number of Eclipse plugins that can be
installed in an <emphasis>Eclipse environment</emphasis>. This
type of environment is created using the function
<varname>eclipseWithPlugins</varname> found inside the
<varname>nixpkgs.eclipses</varname> attribute set. This function
takes as argument <literal>{ eclipse, plugins ? [], jvmArgs ? []
}</literal> where <varname>eclipse</varname> is a one of the
Eclipse packages described above, <varname>plugins</varname> is a
list of plugin derivations, and <varname>jvmArgs</varname> is a
list of arguments given to the JVM running the Eclipse. For
example, say you wish to install the latest Eclipse Platform with
the popular Eclipse Color Theme plugin and also allow Eclipse to
use more RAM. You could then add
<screen>
packageOverrides = pkgs: {
myEclipse = with pkgs.eclipses; eclipseWithPlugins {
eclipse = eclipse-platform;
jvmArgs = [ "-Xmx2048m" ];
plugins = [ plugins.color-theme ];
};
}
</screen>
to your Nixpkgs configuration
(<filename>~/.config/nixpkgs/config.nix</filename>) and install it by
running <command>nix-env -f '<nixpkgs>' -iA
myEclipse</command> and afterward run Eclipse as usual. It is
possible to find out which plugins are available for installation
using <varname>eclipseWithPlugins</varname> by running
<screen>
$ nix-env -f '<nixpkgs>' -qaP -A eclipses.plugins --description
</screen>
</para>
<para>
If there is a need to install plugins that are not available in
Nixpkgs then it may be possible to define these plugins outside
Nixpkgs using the <varname>buildEclipseUpdateSite</varname> and
<varname>buildEclipsePlugin</varname> functions found in the
<varname>nixpkgs.eclipses.plugins</varname> attribute set. Use the
<varname>buildEclipseUpdateSite</varname> function to install a
plugin distributed as an Eclipse update site. This function takes
<literal>{ name, src }</literal> as argument where
<literal>src</literal> indicates the Eclipse update site archive.
All Eclipse features and plugins within the downloaded update site
will be installed. When an update site archive is not available
then the <varname>buildEclipsePlugin</varname> function can be
used to install a plugin that consists of a pair of feature and
plugin JARs. This function takes an argument <literal>{ name,
srcFeature, srcPlugin }</literal> where
<literal>srcFeature</literal> and <literal>srcPlugin</literal> are
the feature and plugin JARs, respectively.
</para>
<para>
Expanding the previous example with two plugins using the above
functions we have
<screen>
packageOverrides = pkgs: {
myEclipse = with pkgs.eclipses; eclipseWithPlugins {
eclipse = eclipse-platform;
jvmArgs = [ "-Xmx2048m" ];
plugins = [
plugins.color-theme
(plugins.buildEclipsePlugin {
name = "myplugin1-1.0";
srcFeature = fetchurl {
url = "http://…/features/myplugin1.jar";
sha256 = "123…";
};
srcPlugin = fetchurl {
url = "http://…/plugins/myplugin1.jar";
sha256 = "123…";
};
});
(plugins.buildEclipseUpdateSite {
name = "myplugin2-1.0";
src = fetchurl {
stripRoot = false;
url = "http://…/myplugin2.zip";
sha256 = "123…";
};
});
];
};
}
</screen>
</para>
</section>
<section xml:id="sec-elm">
<title>Elm</title>
<para>
The Nix expressions for Elm reside in
<filename>pkgs/development/compilers/elm</filename>. They are generated
automatically by <command>update-elm.rb</command> script. One should
specify versions of Elm packages inside the script, clear the
<filename>packages</filename> directory and run the script from inside it.
<literal>elm-reactor</literal> is special because it also has Elm package
dependencies. The process is not automated very much for now -- you should
get the <literal>elm-reactor</literal> source tree (e.g. with
<command>nix-shell</command>) and run <command>elm2nix.rb</command> inside
it. Place the resulting <filename>package.nix</filename> file into
<filename>packages/elm-reactor-elm.nix</filename>.
</para>
</section>
<section xml:id="sec-shell-helpers">
<title>Interactive shell helpers</title>
<para>
Some packages provide the shell integration to be more useful. But
unlike other systems, nix doesn't have a standard share directory
location. This is why a bunch <command>PACKAGE-share</command>
scripts are shipped that print the location of the corresponding
shared folder.
Current list of such packages is as following:
<itemizedlist>
<listitem>
<para>
<literal>autojump</literal>: <command>autojump-share</command>
</para>
</listitem>
<listitem>
<para>
<literal>fzf</literal>: <command>fzf-share</command>
</para>
</listitem>
</itemizedlist>
E.g. <literal>autojump</literal> can then used in the .bashrc like this:
<screen>
source "$(autojump-share)/autojump.bash"
</screen>
</para>
</section>
<section xml:id="sec-steam">
<title>Steam</title>
<section xml:id="sec-steam-nix">
<title>Steam in Nix</title>
<para>
Steam is distributed as a <filename>.deb</filename> file, for now only
as an i686 package (the amd64 package only has documentation).
When unpacked, it has a script called <filename>steam</filename> that
in ubuntu (their target distro) would go to <filename>/usr/bin
</filename>. When run for the first time, this script copies some
files to the user's home, which include another script that is the
ultimate responsible for launching the steam binary, which is also
in $HOME.
</para>
<para>
Nix problems and constraints:
<itemizedlist>
<listitem><para>We don't have <filename>/bin/bash</filename> and many
scripts point there. Similarly for <filename>/usr/bin/python</filename>
.</para></listitem>
<listitem><para>We don't have the dynamic loader in <filename>/lib
</filename>.</para></listitem>
<listitem><para>The <filename>steam.sh</filename> script in $HOME can
not be patched, as it is checked and rewritten by steam.</para></listitem>
<listitem><para>The steam binary cannot be patched, it's also checked.</para></listitem>
</itemizedlist>
</para>
<para>
The current approach to deploy Steam in NixOS is composing a FHS-compatible
chroot environment, as documented
<link xlink:href="http://sandervanderburg.blogspot.nl/2013/09/composing-fhs-compatible-chroot.html">here</link>.
This allows us to have binaries in the expected paths without disrupting the system,
and to avoid patching them to work in a non FHS environment.
</para>
</section>
<section xml:id="sec-steam-play">
<title>How to play</title>
<para>
For 64-bit systems it's important to have
<programlisting>hardware.opengl.driSupport32Bit = true;</programlisting>
in your <filename>/etc/nixos/configuration.nix</filename>. You'll also need
<programlisting>hardware.pulseaudio.support32Bit = true;</programlisting>
if you are using PulseAudio - this will enable 32bit ALSA apps integration.
To use the Steam controller, you need to add
<programlisting>services.udev.extraRules = ''
SUBSYSTEM=="usb", ATTRS{idVendor}=="28de", MODE="0666"
KERNEL=="uinput", MODE="0660", GROUP="users", OPTIONS+="static_node=uinput"
'';</programlisting>
to your configuration.
</para>
</section>
<section xml:id="sec-steam-troub">
<title>Troubleshooting</title>
<para>
<variablelist>
<varlistentry>
<term>Steam fails to start. What do I do?</term>
<listitem><para>Try to run
<programlisting>strace steam</programlisting>
to see what is causing steam to fail.</para></listitem>
</varlistentry>
<varlistentry>
<term>Using the FOSS Radeon or nouveau (nvidia) drivers</term>
<listitem><itemizedlist>
<listitem><para>The <literal>newStdcpp</literal> parameter
was removed after 17.09 release and should not be needed anymore.
</para></listitem>
<listitem><para>
Steam ships statically linked with a version of libcrypto that
conflics with the one dynamically loaded by radeonsi_dri.so.
If you get the error
<programlisting>steam.sh: line 713: 7842 Segmentation fault (core dumped)</programlisting>
have a look at <link xlink:href="https://github.com/NixOS/nixpkgs/pull/20269">this pull request</link>.
</para></listitem>
</itemizedlist></listitem></varlistentry>
<varlistentry>
<term>Java</term>
<listitem><orderedlist>
<listitem><para>
There is no java in steam chrootenv by default. If you get a message like
<programlisting>/home/foo/.local/share/Steam/SteamApps/common/towns/towns.sh: line 1: java: command not found</programlisting>
You need to add
<programlisting> steam.override { withJava = true; };</programlisting>
to your configuration.
</para></listitem>
</orderedlist></listitem></varlistentry>
</variablelist>
</para>
</section>
<section xml:id="sec-steam-run">
<title>steam-run</title>
<para>
The FHS-compatible chroot used for steam can also be used to run
other linux games that expect a FHS environment.
To do it, add
<programlisting>pkgs.(steam.override {
nativeOnly = true;
newStdcpp = true;
}).run</programlisting>
to your configuration, rebuild, and run the game with
<programlisting>steam-run ./foo</programlisting>
</para>
</section>
</section>
<section xml:id="sec-emacs">
<title>Emacs</title>
<section xml:id="sec-emacs-config">
<title>Configuring Emacs</title>
<para>
The Emacs package comes with some extra helpers to make it easier to
configure. <varname>emacsWithPackages</varname> allows you to manage
packages from ELPA. This means that you will not have to install
that packages from within Emacs. For instance, if you wanted to use
<literal>company</literal>, <literal>counsel</literal>,
<literal>flycheck</literal>, <literal>ivy</literal>,
<literal>magit</literal>, <literal>projectile</literal>, and
<literal>use-package</literal> you could use this as a
<filename>~/.config/nixpkgs/config.nix</filename> override:
</para>
<screen>
{
packageOverrides = pkgs: with pkgs; {
myEmacs = emacsWithPackages (epkgs: (with epkgs.melpaStablePackages; [
company
counsel
flycheck
ivy
magit
projectile
use-package
]));
}
}
</screen>
<para>
You can install it like any other packages via <command>nix-env -iA
myEmacs</command>. However, this will only install those packages.
It will not <literal>configure</literal> them for us. To do this, we
need to provide a configuration file. Luckily, it is possible to do
this from within Nix! By modifying the above example, we can make
Emacs load a custom config file. The key is to create a package that
provide a <filename>default.el</filename> file in
<filename>/share/emacs/site-start/</filename>. Emacs knows to load
this file automatically when it starts.
</para>
<screen>
{
packageOverrides = pkgs: with pkgs; rec {
myEmacsConfig = writeText "default.el" ''
;; initialize package
(require 'package)
(package-initialize 'noactivate)
(eval-when-compile
(require 'use-package))
;; load some packages
(use-package company
:bind ("<C-tab>" . company-complete)
:diminish company-mode
:commands (company-mode global-company-mode)
:defer 1
:config
(global-company-mode))
(use-package counsel
:commands (counsel-descbinds)
:bind (([remap execute-extended-command] . counsel-M-x)
("C-x C-f" . counsel-find-file)
("C-c g" . counsel-git)
("C-c j" . counsel-git-grep)
("C-c k" . counsel-ag)
("C-x l" . counsel-locate)
("M-y" . counsel-yank-pop)))
(use-package flycheck
:defer 2
:config (global-flycheck-mode))
(use-package ivy
:defer 1
:bind (("C-c C-r" . ivy-resume)
("C-x C-b" . ivy-switch-buffer)
:map ivy-minibuffer-map
("C-j" . ivy-call))
:diminish ivy-mode
:commands ivy-mode
:config
(ivy-mode 1))
(use-package magit
:defer
:if (executable-find "git")
:bind (("C-x g" . magit-status)
("C-x G" . magit-dispatch-popup))
:init
(setq magit-completing-read-function 'ivy-completing-read))
(use-package projectile
:commands projectile-mode
:bind-keymap ("C-c p" . projectile-command-map)
:defer 5
:config
(projectile-global-mode))
'';
myEmacs = emacsWithPackages (epkgs: (with epkgs.melpaStablePackages; [
(runCommand "default.el" {} ''
mkdir -p $out/share/emacs/site-lisp
cp ${myEmacsConfig} $out/share/emacs/site-lisp/default.el
'')
company
counsel
flycheck
ivy
magit
projectile
use-package
]));
};
}
</screen>
<para>
This provides a fairly full Emacs start file. It will load in
addition to the user's presonal config. You can always disable it by
passing <command>-q</command> to the Emacs command.
</para>
</section>
</section>
</chapter>
|