[gnome-continuous/wip/yocto1.7] Allow overriding ostree-build-yocto and BB_ENV_EXTRAWHITE

[Alexander Larsson <alexl src gnome org>]

commit 1b0361ec1edbcdf3d7f5de65d23927c7e1d51253
Author: Alexander Larsson <alexl redhat com>
Date:   Fri Sep 26 10:37:39 2014 +0200

    Allow overriding ostree-build-yocto and BB_ENV_EXTRAWHITE
    
    If you create a $workdir/overrides/ostree-build-yocto it will be used
    instead of the standard ostree-build-yocto. Also, ostree-build-yocto
    will append OSTREE_BB_ENV_EXTRAWHITE to the BB_ENV_EXTRAWHITE (that
    it sets via oe-init-build-env).
    
    This two changes allow us to use the python27 and git19 scls on rhel6
    by having an override file that does something like:
    
     #!/bin/sh
     OSTREE_BB_ENV_EXTRAWHITE="LD_LIBRARY_PATH" scl enable python27 git19 
"/PREFIX/lib/gnome-continuous/ostree-build-yocto $*"
    
    Where PREFIX is where you installed gnome-continuous.

 src/js/tasks/task-build.js |    9 ++++++++-
 src/ostree-build-yocto     |    2 ++
 2 files changed, 10 insertions(+), 1 deletions(-)
---
diff --git a/src/js/tasks/task-build.js b/src/js/tasks/task-build.js
index 4d0df93..a5ca125 100644
--- a/src/js/tasks/task-build.js
+++ b/src/js/tasks/task-build.js
@@ -1211,7 +1211,14 @@ const TaskBuild = new Lang.Class({
         let sstateDir = oldBuilddir.get_child('sstate-cache');
         let downloads = oldBuilddir.get_child('downloads');
 
-        let cmd = [this.libdir.get_path() + '/ostree-build-yocto',
+        let ostree_build_yocto = this.libdir.get_path() + '/ostree-build-yocto';
+        let overridePath = this.workdir.resolve_relative_path('overrides/ostree-build-yocto');
+        if (overridePath.query_exists(null)) {
+            print("Using override: " + overridePath.get_path());
+            ostree_build_yocto = overridePath.get_path();
+        }
+
+        let cmd = [ostree_build_yocto,
                   checkoutdir.get_path(), builddir.get_path(), architecture,
                   this.repo.get_path()];
         // We specifically want to kill off any environment variables jhbuild
diff --git a/src/ostree-build-yocto b/src/ostree-build-yocto
index e8d9f90..9173b22 100644
--- a/src/ostree-build-yocto
+++ b/src/ostree-build-yocto
@@ -46,6 +46,8 @@ for layername in ${LAYERNAMES}; do
     LAYERS="${LAYERS} \${OSTREE_SRCDIR}/${layername}"
 done
 
+BB_ENV_EXTRAWHITE="$BB_ENV_EXTRAWHITE $OSTREE_BB_ENV_EXTRAWHITE"
+
 cat > ${builddir}/conf/bblayers.conf <<EOF
 # LAYER_CONF_VERSION is increased each time build/conf/bblayers.conf
 # changes incompatibly