bitbake.conf: set BB_DEFAULT_UMASK using ??=

Currently, there's no way for the user's site.conf, local.conf or
similar to set BB_DEFAULT_UMASK, because those files are included by
bitbake.conf prior to the unconditional assignment of
BB_DEFAULT_UMASK. To make that possible, use a weak default assignment
instead. This is also consistent with most other variable assignments
in the lower half of bitbake.conf.

I believe the risk of a regression is very small; it would require
something like somebody having a definition of BB_DEFAULT_UMASK in a
local configuration file, and having been relying on that _not_ taking
effect.

(From OE-Core rev: 4d603ccf0713ade69d98e452b991a4d1d71c144a)

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
(cherry picked from commit e3dbded499f0bd1e71abb0650ae98fd9ade94250)
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index 2a3cf6f8aa..516a30c963 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -924,7 +924,7 @@ SHELL[unexport] = "1"
 TRANSLATED_TARGET_ARCH ??= "${@d.getVar('TARGET_ARCH').replace("_", "-")}"
 
 # Set a default umask to use for tasks for determinism
-BB_DEFAULT_UMASK = "022"
+BB_DEFAULT_UMASK ??= "022"
 
 # Complete output from bitbake
 BB_CONSOLELOG ?= "${LOG_DIR}/cooker/${MACHINE}/${DATETIME}.log"