pin cuda and gdrcopy variants for ucx

config/specific/m100/packages.yaml

@@ -77,6 +77,11 @@ packages:
       - +cuda
       - ~cxx_exceptions
 
+  ucx:
+    variants:
+      - +cuda
+      - +gdrcopy
+
 #  essl:
 #    paths:
 #      essl@6.2.1%gcc@7.4.0: /cineca/prod/opt/libraries/essl/6.2.1/binary