Merge pull request #2882 from grahamc/docs/1115-tarball-ttl

tarball-ttl: document
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Eelco Dolstra 2019-07-06 00:15:27 +02:00 committed by GitHub
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2 changed files with 27 additions and 2 deletions

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@ -864,6 +864,31 @@ requiredSystemFeatures = [ "kvm" ];
</varlistentry>
<varlistentry xml:id="conf-tarball-ttl"><term><literal>tarball-ttl</literal></term>
<listitem>
<para>Default: <literal>3600</literal> seconds.</para>
<para>The number of seconds a downloaded tarball is considered
fresh. If the cached tarball is stale, Nix will check whether
it is still up to date using the ETag header. Nix will download
a new version if the ETag header is unsupported, or the
cached ETag doesn't match.
</para>
<para>Setting the TTL to <literal>0</literal> forces Nix to always
check if the tarball is up to date.</para>
<para>Nix caches tarballs in
<filename>$XDG_CACHE_HOME/nix/tarballs</filename>.</para>
<para>Files fetched via <envar>NIX_PATH</envar>,
<function>fetchGit</function>, <function>fetchMercurial</function>,
<function>fetchTarball</function>, and <function>fetchurl</function>
respect this TTL.
</para>
</listitem>
</varlistentry>
<varlistentry xml:id="conf-timeout"><term><literal>timeout</literal></term>

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@ -347,7 +347,7 @@ stdenv.mkDerivation { … }
You can change the cache timeout either on the command line with
<option>--option tarball-ttl <replaceable>number of seconds</replaceable></option> or
in the Nix configuration file with this option:
<literal>tarball-ttl <replaceable>number of seconds to cache</replaceable></literal>.
<literal><xref linkend="conf-tarball-ttl" /> <replaceable>number of seconds to cache</replaceable></literal>.
</para>
<para>Note that when obtaining the hash with <varname>nix-prefetch-url
@ -513,7 +513,7 @@ stdenv.mkDerivation { … }
fetch the latest version of a remote branch.
</para>
<note><para>Nix will refetch the branch in accordance to
<option>tarball-ttl</option>.</para></note>
<xref linkend="conf-tarball-ttl" />.</para></note>
<note><para>This behavior is disabled in
<emphasis>Pure evaluation mode</emphasis>.</para></note>
<programlisting>builtins.fetchGit {