[Q][PATCH 2/5] UBUNTU: [Packaging] debian/rules.d/0-common-vars.mk: avoid infinite loop

[Zixing Liu]

This patch changes the eager evalution of various DEB_* variables to
optionally evaluated to avoid Make infinite looping itself if DEB_*
variables are set ahead of time.

Signed-off-by: Zixing Liu <zixing.liu at canonical.com>
---
 debian/rules.d/0-common-vars.mk | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/debian/rules.d/0-common-vars.mk b/debian/rules.d/0-common-vars.mk
index 4d383b65962d..59e25d9672f3 100644
--- a/debian/rules.d/0-common-vars.mk
+++ b/debian/rules.d/0-common-vars.mk
@@ -69,11 +69,11 @@ ifneq ($(do_full_build),false)
   uploadnum	:= $(uploadnum)-Ubuntu
 endif
 
-DEB_HOST_MULTIARCH = $(shell dpkg-architecture -qDEB_HOST_MULTIARCH)
-DEB_HOST_GNU_TYPE  = $(shell dpkg-architecture -qDEB_HOST_GNU_TYPE)
-DEB_BUILD_GNU_TYPE = $(shell dpkg-architecture -qDEB_BUILD_GNU_TYPE)
-DEB_HOST_ARCH = $(shell dpkg-architecture -qDEB_HOST_ARCH)
-DEB_BUILD_ARCH = $(shell dpkg-architecture -qDEB_BUILD_ARCH)
+DEB_HOST_MULTIARCH ?= $(shell dpkg-architecture -qDEB_HOST_MULTIARCH)
+DEB_HOST_GNU_TYPE  ?= $(shell dpkg-architecture -qDEB_HOST_GNU_TYPE)
+DEB_BUILD_GNU_TYPE ?= $(shell dpkg-architecture -qDEB_BUILD_GNU_TYPE)
+DEB_HOST_ARCH ?= $(shell dpkg-architecture -qDEB_HOST_ARCH)
+DEB_BUILD_ARCH ?= $(shell dpkg-architecture -qDEB_BUILD_ARCH)
 
 #
 # Detect invocations of the form 'fakeroot debian/rules binary arch=armhf'
-- 
2.48.1