[PATCH(sbuild) 1/1] avoid absolute SCHROOT_* paths to improve caching

[Felix Moessbauer <felix.moessbauer@siemens.com>]

This patch reworks the logic to setup the SCHROOT_* bitbake
variables by making sure nothing is expanded.
By that, no absolute paths into the build host are exposed,
which finally makes the recipe cachable.

Signed-off-by: Felix Moessbauer <felix.moessbauer@siemens.com>
---
 meta/classes/sbuild.bbclass | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/meta/classes/sbuild.bbclass b/meta/classes/sbuild.bbclass
index 760a0203..0ea26181 100644
--- a/meta/classes/sbuild.bbclass
+++ b/meta/classes/sbuild.bbclass
@@ -14,11 +14,11 @@ python __anonymous() {
     if mode == "0" or d.getVar('HOST_ARCH') ==  distro_arch or \
        (d.getVar('HOST_DISTRO') == "debian-stretch" and distro_arch == "i386"):
         d.setVar('SBUILD_HOST_ARCH', distro_arch)
-        d.setVar('SCHROOT_DIR', d.getVar('SCHROOT_TARGET_DIR'))
+        d.setVar('SCHROOT_DIR', d.getVar('SCHROOT_TARGET_DIR', False))
         dep = "sbuild-chroot-target:do_build"
     else:
         d.setVar('SBUILD_HOST_ARCH', d.getVar('HOST_ARCH'))
-        d.setVar('SCHROOT_DIR', d.getVar('SCHROOT_HOST_DIR'))
+        d.setVar('SCHROOT_DIR', d.getVar('SCHROOT_HOST_DIR', False))
         dep = "sbuild-chroot-host:do_build"
     d.setVar('SCHROOT_DEP', dep)
 }
-- 
2.30.2