contribs: osx: additional check for SDKROOT location alternative

Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

contrib/bootstrap

@@ -150,6 +150,13 @@ check_macosx_sdk()
       echo "SDKROOT not specified, assuming $SDKROOT"
    fi
 
+   if [ ! -d "${SDKROOT}" ]
+   then
+      SDKROOT_NOT_FOUND=`xcode-select -print-path`/Platforms/MacOSX.platform/Developer/SDKs/MacOSX$OSX_VERSION.sdk
+      SDKROOT=`xcode-select -print-path`/SDKs/MacOSX$OSX_VERSION.sdk
+      echo "SDKROOT not found at $SDKROOT_NOT_FOUND, trying $SDKROOT"
+   fi
+
    if [ ! -d "${SDKROOT}" ]
    then
       echo "*** ${SDKROOT} does not exist, please install required SDK, or set SDKROOT manually. ***"