man: reword description of BUILD_ID in os-release

Our description was pretty hard to parse. Let's replace it with a description
loosely based on a fairly clear description written by a distro that actually
uses BUILD_ID:
https://developer.rigado.com/docsets/Working-with-the-Rigado-Vesta-Gateway/latest/production/versioning-images.html#the-rigos-scheme.
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2021-05-20 20:37:55 +02:00
parent 3ca606d103
commit 8fd67ab5a3

View file

@ -224,12 +224,13 @@
<varlistentry>
<term><varname>BUILD_ID=</varname></term>
<listitem><para>A string uniquely identifying the system image used as the origin for a distribution
(it is not updated with system updates). The field can be identical between different
<varname>VERSION_ID</varname>s as <varname>BUILD_ID</varname> is an only a unique identifier to a
specific version. Distributions that release each update as a new version would only need to use
<varname>VERSION_ID</varname> as each build is already distinct based on the
<varname>VERSION_ID</varname>. This field is optional.</para>
<listitem><para>A string uniquely identifying the system image originally used as the installation
base. In most cases, <varname>VERSION_ID</varname> or
<varname>IMAGE_ID</varname>+<varname>IMAGE_VERSION</varname> are updated when the entire system
image is replaced during an update. <varname>BUILD_ID</varname> may be used in distributions where
the original installation image version is important: <varname>VERSION_ID</varname> would change
during incremental system updates, but <varname>BUILD_ID</varname> would not. This field is
optional.</para>
<para>Examples: <literal>BUILD_ID="2013-03-20.3"</literal>, <literal>BUILD_ID=201303203</literal>.
</para></listitem>
@ -261,6 +262,13 @@
</para></listitem>
</varlistentry>
</variablelist>
<para>To summarize: if the image updates are built and shipped as comprehensive units,
<varname>IMAGE_ID</varname>+<varname>IMAGE_VERSION</varname> is the best fit. Otherwise, if updates
eventually completely replace previously installed contents, as in a typical binary distribution,
<varname>VERSION_ID</varname> should be used to identify major releases of the operating system.
<varname>BUILD_ID</varname> may be used instead or in addition to <varname>VERSION_ID</varname> when
the original system image version is important.</para>
</refsect2>
<refsect2>