scons: Don't use isdir in AddLocalRPATH.

isdir isn't a nice way to check if an FS.Base is a File or a Dir as was
initially assumed, it literally checks if a path can be stat-ed and is
reported as a directory by stat. This means that if a directory is
going to be created as part of the build, the result of that test will
change depending on whether that part of the build has happened
successfully before.

A better check which behaves as originally intended is to check whether
the Node is an instance of the SCons.Node.FS.Dir class.

Change-Id: Id041917d50b768a8205769c0a05320f92b09993c
Reviewed-by: Jason Lowe-Power <>
Maintainer: Gabe Black <>
diff --git a/SConstruct b/SConstruct
index 3599371..53b8c9d 100755
--- a/SConstruct
+++ b/SConstruct
@@ -97,6 +97,7 @@
 # SCons includes
 import SCons
 import SCons.Node
+import SCons.Node.FS
 from m5.util import compareVersions, readCommand
@@ -1096,7 +1097,7 @@
     for target in targets:
         target = env.Entry(target)
-        if not target.isdir():
+        if not isinstance(target, SCons.Node.FS.Dir):
             target = target.dir
         relpath = os.path.relpath(target.abspath, env['BUILDDIR'])
         components = [