Readd check for if variant_root exists, but only if repository type i…

…s filesystem

Signed-off-by: Bryce Gattis <[email protected]>

src/rez/package_cache.py

@@ -165,6 +165,12 @@ def add_variant(self, variant, force=False):
                 % variant.uri
             )
 
+        if package.repository.name() == "filesystem" and not os.path.isdir(variant_root):
+            raise PackageCacheError(
+                "Not cached - variant %s root does not appear on disk: %s"
+                % (variant.uri, variant_root)
+            )
+
         if not force:
             # package is configured to not be cachable
             if not package.is_cachable: