[PATCH] dev-manual: correct which package variables support which backends

Update the section "Excluding packages from an image" to explain that
all packaging backends support all three package exclusion variables,
with the single exception that Debian packaging does not support
BAD_RECOMMENDATIONS.

Signed-off-by: Robert P. J. Day <[email protected]>

---

  i tested with adding "minicom" to an image, then trying to exclude
its recommendation of "lrzsz".

diff --git a/documentation/dev-manual/packages.rst b/documentation/dev-manual/packages.rst
index 500639565..80bcac0ba 100644
--- a/documentation/dev-manual/packages.rst
+++ b/documentation/dev-manual/packages.rst
@@ -30,13 +30,10 @@ installed into an image. If so, you can use several variables to direct
 the build system to essentially ignore installing recommended packages
 or to not install a package at all.

-The following list introduces variables you can use to prevent packages
-from being installed into your image. Each of these variables only works
-with IPK and RPM package types, not for Debian packages.
-Also, you can use these variables from your ``local.conf`` file
-or attach them to a specific image recipe by using a recipe name
-override. For more detail on the variables, see the descriptions in the
-Yocto Project Reference Manual's glossary chapter.
+There are three variables you can use to avoid installing particular
+packages into the final image -- you can either set these variables
+appropriately in your ``local.conf`` file, or attach them to a specific
+image recipe by using a recipe name override.

 -  :term:`BAD_RECOMMENDATIONS`:
    Use this variable to specify "recommended-only" packages that you do
@@ -53,6 +50,19 @@ Yocto Project Reference Manual's glossary chapter.
    prevent the installation of a package whose presence is required by
    an installed package.

+.. warning::
+
+   All three of these package exclusion variables work with all three
+   packaging backends (DEB, RPM and IPK) with one exception:
+   Debian packaging does not support the ``BAD_RECOMMENDATIONS`` setting.
+   If you try that combination, you will get a warning similar to::
+
+      WARNING: core-image-minimal-1.0-r0 do_rootfs:
+        Debian package install does not support BAD_RECOMMENDATIONS
+
+   All of the other combinations of packaging backend and exclusion
+   variable are supported.
+
 Incrementing a Package Version
 ==============================