ncl: add RPC lib with ncl+hdf4 (#34451)

var/spack/repos/builtin/packages/ncl/package.py

@@ -17,9 +17,11 @@ class Ncl(Package):
     Numerous analysis functions are built-in."""
 
     homepage = "https://www.ncl.ucar.edu"
-
+    git = "https://github.com/NCAR/ncl.git"
     url = "https://github.com/NCAR/ncl/archive/6.4.0.tar.gz"
 
+    maintainers = ["vanderwb"]
+
     version("6.6.2", sha256="cad4ee47fbb744269146e64298f9efa206bc03e7b86671e9729d8986bb4bc30e")
     version("6.5.0", sha256="133446f3302eddf237db56bf349e1ebf228240a7320699acc339a3d7ee414591")
     version("6.4.0", sha256="0962ae1a1d716b182b3b27069b4afe66bf436c64c312ddfcf5f34d4ec60153c8")
@@ -293,6 +295,15 @@ def prepare_install_config(self):
         with open(config_answers_filename, "r") as f:
             config_script(input=f)
 
+        if self.spec.satisfies("^hdf+external-xdr") and not self.spec["hdf"].satisfies("^libc"):
+            hdf4 = self.spec["hdf"]
+
+            filter_file(
+                "(#define HDFlib.*)",
+                r"\1 {}".format(hdf4["rpc"].libs.link_flags),
+                "config/Site.local",
+            )
+
     def prepare_src_tree(self):
         if "+triangle" in self.spec:
             triangle_src = join_path(self.stage.source_path, "triangle_src")