Edit EP file to make it use CMake.

CMake/External_SuiteSparse.cmake

@@ -60,6 +60,7 @@ elseif (NOT WIN32 AND NOT BUILD_CXSPARSE_ONLY)
     set(SUITESPARSE_BLAS "-framework Accelerate")
   endif()
 
+  set(SuiteSparse_LINKER_LAPACK_BLAS_LIBS ${SUITESPARSE_LAPACK} ${SUITESPARSE_BLAS})
   find_library(LIBRT_LIBRARY rt)
   mark_as_advanced(LIBRT_LIBRARY)
   set(SUITESPARSE_LIBRT ${LIBRT_LIBRARY})
@@ -72,13 +73,12 @@ elseif (NOT WIN32 AND NOT BUILD_CXSPARSE_ONLY)
   # Make sure the install directories are created, which is not a guarantee with SuiteSparse built alone (first)
   file(MAKE_DIRECTORY ${fletch_BUILD_INSTALL_PREFIX}/include)
   file(MAKE_DIRECTORY ${fletch_BUILD_INSTALL_PREFIX}/lib)
-  Fletch_Require_Make()
   ExternalProject_Add(SuiteSparse
     DEPENDS ${SuiteSparse_DEPENDS}
     URL ${SuiteSparse_file}
     URL_MD5 ${SuiteSparse_md5}
     ${COMMON_EP_ARGS}
-    BUILD_IN_SOURCE 1
+    ${COMMON_CMAKE_EP_ARGS}
     PATCH_COMMAND ${CMAKE_COMMAND}
       -DSuiteSparse_patch=${fletch_SOURCE_DIR}/Patches/SuiteSparse
       -DSuiteSparse_source=${fletch_BUILD_PREFIX}/src/SuiteSparse
@@ -89,10 +89,11 @@ elseif (NOT WIN32 AND NOT BUILD_CXSPARSE_ONLY)
       -DLIBRT_LIBRARY=${SUITESPARSE_LIBRT}
       -DSUITESPARSE_NOTIMER=${SUITESPARSE_NOTIMER}
       -P ${fletch_SOURCE_DIR}/Patches/SuiteSparse/Patch.cmake
-
-    CONFIGURE_COMMAND ""
-    BUILD_COMMAND ${MAKE_EXECUTABLE} -j1
-    INSTALL_COMMAND ${MAKE_EXECUTABLE} install
+    CMAKE_ARGS
+      ${COMMON_CMAKE_ARGS}
+      -DBUILD_SHARED_LIBS:BOOL=${BUILD_SHARED_LIBS}
+      -DSuiteSparse_LINKER_LAPACK_BLAS_LIBS=${SuiteSparse_LINKER_LAPACK_BLAS_LIBS}
+      -DHAVE_COMPLEX:BOOL=ON
     )
 
 endif()