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
|
<section xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xml:id="sec-custom-packages">
<title>Adding Custom Packages</title>
<para>
It’s possible that a package you need is not available in NixOS. In
that case, you can do two things. Either you can package it with
Nix, or you can try to use prebuilt packages from upstream. Due to
the peculiarities of NixOS, it is important to note that building
software from source is often easier than using pre-built
executables.
</para>
<section xml:id="sec-custom-packages-nix">
<title>Building with Nix</title>
<para>
This can be done either in-tree or out-of-tree. For an in-tree
build, you can clone the Nixpkgs repository, add the package to
your clone, and (optionally) submit a patch or pull request to
have it accepted into the main Nixpkgs repository. This is
described in detail in the
<link xlink:href="https://nixos.org/nixpkgs/manual">Nixpkgs
manual</link>. In short, you clone Nixpkgs:
</para>
<programlisting>
$ git clone https://github.com/NixOS/nixpkgs
$ cd nixpkgs
</programlisting>
<para>
Then you write and test the package as described in the Nixpkgs
manual. Finally, you add it to
<xref linkend="opt-environment.systemPackages" />, e.g.
</para>
<programlisting language="bash">
environment.systemPackages = [ pkgs.my-package ];
</programlisting>
<para>
and you run <literal>nixos-rebuild</literal>, specifying your own
Nixpkgs tree:
</para>
<programlisting>
# nixos-rebuild switch -I nixpkgs=/path/to/my/nixpkgs
</programlisting>
<para>
The second possibility is to add the package outside of the
Nixpkgs tree. For instance, here is how you specify a build of the
<link xlink:href="https://www.gnu.org/software/hello/">GNU
Hello</link> package directly in
<literal>configuration.nix</literal>:
</para>
<programlisting language="bash">
environment.systemPackages =
let
my-hello = with pkgs; stdenv.mkDerivation rec {
name = "hello-2.8";
src = fetchurl {
url = "mirror://gnu/hello/${name}.tar.gz";
sha256 = "0wqd8sjmxfskrflaxywc7gqw7sfawrfvdxd9skxawzfgyy0pzdz6";
};
};
in
[ my-hello ];
</programlisting>
<para>
Of course, you can also move the definition of
<literal>my-hello</literal> into a separate Nix expression, e.g.
</para>
<programlisting language="bash">
environment.systemPackages = [ (import ./my-hello.nix) ];
</programlisting>
<para>
where <literal>my-hello.nix</literal> contains:
</para>
<programlisting language="bash">
with import <nixpkgs> {}; # bring all of Nixpkgs into scope
stdenv.mkDerivation rec {
name = "hello-2.8";
src = fetchurl {
url = "mirror://gnu/hello/${name}.tar.gz";
sha256 = "0wqd8sjmxfskrflaxywc7gqw7sfawrfvdxd9skxawzfgyy0pzdz6";
};
}
</programlisting>
<para>
This allows testing the package easily:
</para>
<programlisting>
$ nix-build my-hello.nix
$ ./result/bin/hello
Hello, world!
</programlisting>
</section>
<section xml:id="sec-custom-packages-prebuilt">
<title>Using pre-built executables</title>
<para>
Most pre-built executables will not work on NixOS. There are two
notable exceptions: flatpaks and AppImages. For flatpaks see the
<link linkend="module-services-flatpak">dedicated section</link>.
AppImages will not run <quote>as-is</quote> on NixOS. First you
need to install <literal>appimage-run</literal>: add to
<literal>/etc/nixos/configuration.nix</literal>
</para>
<programlisting language="bash">
environment.systemPackages = [ pkgs.appimage-run ];
</programlisting>
<para>
Then instead of running the AppImage <quote>as-is</quote>, run
<literal>appimage-run foo.appimage</literal>.
</para>
<para>
To make other pre-built executables work on NixOS, you need to
package them with Nix and special helpers like
<literal>autoPatchelfHook</literal> or
<literal>buildFHSUserEnv</literal>. See the
<link xlink:href="https://nixos.org/nixpkgs/manual">Nixpkgs
manual</link> for details. This is complex and often doing a
source build is easier.
</para>
</section>
</section>
|