scons: scons not always rebuilding a target when the source changes.

Tell scons to check file timestamps to see is source newer than
target.  Before, if target existed, not rebuilt when shouce changed.

1 files changed, 4 insertions, 0 deletions

diff --git a/SConstruct b/SConstruct
index 040103cf..3ef9ebc3 100644
--- a/SConstruct
+++ b/SConstruct
@@ -118,6 +118,10 @@ def filtered_spawn(sh, escape, cmd, args, env):
 # Build-control options
 #
 
+# without this, scons will not rebuild an existing target when the
+# source changes.
+Decider('timestamp-match')
+
 # Start by reading configuration variables from the cache
 opts = Variables('.scons-option-cache')