rename build-extra-platforms -> extra-platforms

also document it
This commit is contained in:
Linus Heckemann 2018-03-16 22:50:27 +00:00
parent 919c3c20b3
commit 637701b604
2 changed files with 25 additions and 2 deletions

View file

@ -254,6 +254,25 @@ false</literal>.</para>
</varlistentry>
<varlistentry><term><literal>extra-platforms</literal></term>
<listitem><para>Platforms other than the native one which
this machine is capable of building for. This can be useful for
supporting additional architectures on compatible machines:
i686-linux can be built on x86_64-linux machines (and the default
for this setting reflects this); armv7 is backwards-compatible with
armv6 and armv5tel; some aarch64 machines can also natively run
32-bit ARM code; and qemu-user may be used to support non-native
platforms (though this may be slow and buggy). Most values for this
are not enabled by default because build systems will often
misdetect the target platform and generate incompatible code, so you
may wish to cross-check the results of using this option against
proper natively-built versions of your
derivations.</para></listitem>
</varlistentry>
<varlistentry><term><literal>extra-substituters</literal></term>
<listitem><para>Additional binary caches appended to those

View file

@ -295,8 +295,12 @@ public:
"Nix store has a valid signature (that is, one signed using a key "
"listed in 'trusted-public-keys'."};
Setting<StringSet> extraPlatforms{this, StringSet{}, "build-extra-platforms",
"Additional platforms that can be built on the local system, e.g. using qemu-user."};
Setting<StringSet> extraPlatforms{this,
SYSTEM == "x86_64-linux" ? StringSet{"i686-linux"} : StringSet{},
"extra-platforms",
"Additional platforms that can be built on the local system. "
"These may be supported natively (e.g. armv7 on some aarch64 CPUs "
"or using hacks like qemu-user."};
Setting<Strings> substituters{this,
nixStore == "/nix/store" ? Strings{"https://cache.nixos.org/"} : Strings(),