utils.py: Don't error if an exported environment variable is unset (i.e. None)

(From Poky rev: 62c103ce0e154ee5bf6183987adc90fc6df154c6)

Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

diff --git a/lib/bb/utils.py b/lib/bb/utils.py
index 5fc1463e678c7f876894839a8c4a879e59a3f7fe..3b7ea2e83c2b8c6e97858d0d7e63c0212263fe34 100644 (file)
--- a/lib/bb/utils.py
+++ b/lib/bb/utils.py
@@ -403,7 +403,7 @@ def build_environment(d):
     for var in bb.data.keys(d):
         export = bb.data.getVarFlag(var, "export", d)
         if export:
-            os.environ[var] = bb.data.getVar(var, d, True)
+            os.environ[var] = bb.data.getVar(var, d, True) or ""
 
 def prunedir(topdir):
     # Delete everything reachable from the directory named in 'topdir'.