missing dependencies (m4) added for netcdf and autoconf

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

@@ -8,6 +8,8 @@ class Autoconf(Package):
     version('2.69', '82d05e03b93e45f5a39b828dc9c6c29b')
     version('2.62', '6c1f3b3734999035d77da5024aab4fbd')
 
+    depends_on("m4")
+
     def install(self, spec, prefix):
         configure("--prefix=%s" % prefix)
 

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

@@ -21,6 +21,7 @@ class Netcdf(Package):
     depends_on("hdf5+mpi~cxx", when='+mpi')  # required for NetCDF-4 support
     depends_on("hdf5~mpi", when='~mpi')  # required for NetCDF-4 support
     depends_on("zlib")  # required for NetCDF-4 support
+    depends_on("m4")
 
     def install(self, spec, prefix):
         # Environment variables