[gtk-osx: 1/4] Fix SDKROOT setup if it is already defined

[John Ralls <jralls src gnome org>]

commit 66d8da77ffb2f53528f1dcbc4c14895f3282d799
Author: Alex Samorukov <samm os2 kiev ua>
Date:   Sun Nov 25 16:54:45 2018 +0100

    Fix SDKROOT setup if it is already defined

 jhbuildrc-gtk-osx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/jhbuildrc-gtk-osx b/jhbuildrc-gtk-osx
index 41ced0a..499a6dc 100644
--- a/jhbuildrc-gtk-osx
+++ b/jhbuildrc-gtk-osx
@@ -229,7 +229,7 @@ def setup_sdk(target=_target, sdk_version=None, architectures=[_default_arch]):
         # developing, and it takes a lot of typing, so define a
         # convenience environment variable:
         environ_append('SDKDIR', sdkdir)
-        environ_append('SDKROOT', sdkdir)
+        os.environ["SDKROOT"] = sdkdir
 
         # Apple Documentation says that "-syslibroot" is the arg to pass to the
         # linker, but we are using the compiler to control the linker, and