Fix PR awslabs#717 MFEM patch stack and Spack cuDSS support

Author: hughcars

.github/license-check/c.txt

@@ -1,2 +1 @@
-// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0

cmake/ExternalGitTags.cmake

@@ -125,15 +125,15 @@ set(EXTERN_METIS_GIT_TAG
 
 # MFEM
 set(EXTERN_MFEM_URL
-  "https://github.com/yuyangdai/mfem.git" CACHE STRING
+  "https://github.com/mfem/mfem.git" CACHE STRING
   "URL for external MFEM build"
 )
 set(EXTERN_MFEM_GIT_BRANCH
-  "cudss-dev" CACHE STRING
+  "master" CACHE STRING
   "Git branch for external MFEM build"
 )
 set(EXTERN_MFEM_GIT_TAG
-  "e217864f168acb1d7bdb3fd7c5aa73ef81951237" CACHE STRING
+  "d9d6526cc1749980a2ba1da16e2c1ca1e07d82ec" CACHE STRING
   "Git tag for external MFEM build"
 )
 

cmake/ExternalMFEM.cmake

@@ -123,7 +123,7 @@ if(PALACE_WITH_CUDA)
     "-DCMAKE_CUDA_FLAGS=${MFEM_CUDA_FLAGS}"
     "-DMFEM_USE_CUDSS=${PALACE_WITH_CUDSS}"
   )
-  if(PALACE_WITH_CUDSS)
+  if(PALACE_WITH_CUDSS AND NOT "${CUDSS_DIR}" STREQUAL "")
     list(APPEND MFEM_OPTIONS
       "-DCUDSS_DIR=${CUDSS_DIR}"
     )
@@ -406,6 +406,8 @@ set(MFEM_PATCH_FILES
   "${CMAKE_SOURCE_DIR}/extern/patch/mfem/patch_par_tet_mesh_fix_dev.diff"
   "${CMAKE_SOURCE_DIR}/extern/patch/mfem/patch_gmsh_parser_performance.diff"
   "${CMAKE_SOURCE_DIR}/extern/patch/mfem/mfem_pr5280.diff"
+  "${CMAKE_SOURCE_DIR}/extern/patch/mfem/mfem_pr5246.diff"
+  "${CMAKE_SOURCE_DIR}/extern/patch/mfem/mfem_pr5124_cudss.diff"
 )
 
 include(ExternalProject)