multilib.bbclass/package_manager.py: fix <multilib>-meta-toolchain build failure

There is a failure to build lib32-meta-toolchain:
...
|ERROR: lib32-packagegroup-core-standalone-sdk-target not found in the base
feeds (qemux86_64 x86 noarch any all).
...

In package_manager.py, the variable 'DEFAULTTUNE_virtclass-multilib-lib32'
is used to process multilib image/toolchain. But for the build of lib32-
meta-toolchain, the value of 'DEFAULTTUNE_virtclass-multilib-lib32' is
deleted. In 'bitbake lib32-meta-toolchain -e', we got:
...
|# $DEFAULTTUNE_virtclass-multilib-lib32 [2 operations]
|#   set? /home/jiahongxu/yocto/build-20141010-yocto/conf/local.conf:237
|#     "x86"
|#   del data_smart.py:406 [finalize]
|#     ""
|# pre-expansion value:
|#   "None"
...

The commit 899d45b90061eb3cf3e71029072eee42cd80930c in oe-core deleted
it at DataSmart.finalize
...
Author: Richard Purdie <richard.purdie@linuxfoundation.org>
Date:   Tue May 31 23:52:50 2011 +0100

    bitbake/data_smart: Change overrides behaviour to remove
       expanded variables from the datastore
...

We add an internal variable 'DEFAULTTUNE_ML_<multilib>', assign it with the
value of 'DEFAULTTUNE_virtclass-multilib-lib32' before deleting.

For rpm backend in package_manager.py, we use DEFAULTTUNE_virtclass-multilib
-lib32 first, if it is not available, and try to use DEFAULTTUNE_ML_<multilib>

[YOCTO #6842]

Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/meta/classes/multilib.bbclass b/meta/classes/multilib.bbclass
index 2a90d9ef29..eea2fd59a1 100644
--- a/meta/classes/multilib.bbclass
+++ b/meta/classes/multilib.bbclass
@@ -63,6 +63,7 @@ python multilib_virtclass_handler () {
     newtune = e.data.getVar("DEFAULTTUNE_" + "virtclass-multilib-" + variant, False)
     if newtune:
         e.data.setVar("DEFAULTTUNE", newtune)
+        e.data.setVar('DEFAULTTUNE_ML_%s' % variant, newtune)
 }
 
 addhandler multilib_virtclass_handler