ref-manual: Added note to PROVIDES variable description.

Fixes [YOCTO #10069]

Added a note at the end of the variable description to
explain how runtime virual dependencies work.

(From yocto-docs rev: de1d16017c27b6b2502735fc41acd22660f6e7b9)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index 2507d4b520..8ff0d671d1 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -10042,6 +10042,23 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
                     <link linkend='var-PREFERRED_PROVIDER'><filename>PREFERRED_PROVIDER</filename></link>
                     variable is used to select which particular recipe
                     provides a virtual target.
+                    <note>
+                        <para>A corresponding mechanism for virtual runtime
+                        dependencies (packages) exists.
+                        However, the mechanism does not depend on any special
+                        functionality beyond ordinary variable assignments.
+                        For example,
+                        <filename>VIRTUAL-RUNTIME_dev_manager</filename>
+                        refers to the package of the component that manages
+                        the <filename>/dev</filename> directory.</para>
+
+                        <para>Setting the "preferred provider" for runtime
+                        dependencies is as simple as using the following
+                        assignment in a configuration file:</para>
+                        <literallayout class='monospaced'>
+     VIRTUAL-RUNTIME_dev_manager = "udev"
+                        </literallayout>
+                    </note>
                 </para>
             </glossdef>
         </glossentry>