1 files changed, 9 insertions, 1 deletions

diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
index 6b9f9798db..0e81b4e7e0 100644
--- a/meta/classes/image.bbclass
+++ b/meta/classes/image.bbclass
@@ -297,7 +297,15 @@ python setup_debugfs () {
 
 python () {
     vardeps = set()
-    ctypes = d.getVar('COMPRESSIONTYPES', True).split()
+    # We allow COMPRESSIONTYPES to have duplicates. That avoids breaking
+    # derived distros when OE-core or some other layer independently adds
+    # the same type. There is still only one command for each type, but
+    # presumably the commands will do the same when the type is the same,
+    # even when added in different places.
+    #
+    # Without de-duplication, gen_conversion_cmds() below
+    # would create the same compression command multiple times.
+    ctypes = set(d.getVar('COMPRESSIONTYPES', True).split())
     old_overrides = d.getVar('OVERRIDES', 0)
 
     def _image_base_type(type):