diff -urN petsc-3.13.5.orig/config/BuildSystem/config/packages/MPI.py petsc-3.13.5/config/BuildSystem/config/packages/MPI.py
--- petsc-3.13.5.orig/config/BuildSystem/config/packages/MPI.py	2020-07-02 06:50:43.000000000 +0500
+++ petsc-3.13.5/config/BuildSystem/config/packages/MPI.py	2020-10-03 19:01:00.180021500 +0500
@@ -14,7 +14,7 @@
     config.package.Package.__init__(self, framework)
     self.minversion         = '2'
     self.versionname        = 'MPI_VERSION'
-    self.functions          = ['MPI_Init', 'MPI_Comm_create']
+    self.functions          = []
     self.includes           = ['mpi.h']
     liblist_mpich         = [['fmpich2.lib','fmpich2g.lib','fmpich2s.lib','mpi.lib'],
                              ['fmpich2.lib','fmpich2g.lib','mpi.lib'],['fmpich2.lib','mpich2.lib'],
@@ -289,6 +289,8 @@
     # flag broken one-sided tests
     if not 'HAVE_MSMPI' in self.defines and not (hasattr(self, 'mpich_numversion') and int(self.mpich_numversion) <= 30004300):
       self.addDefine('HAVE_MPI_ONE_SIDED', 1)
+    for f in '''MPI_Comm_spawn MPI_Type_get_envelope MPI_Type_get_extent MPI_Type_dup MPI_Init_thread MPI_Finalized MPI_Exscan'''.split():
+      self.addDefine('HAVE_' + f.upper(),1)
     self.compilers.CPPFLAGS = oldFlags
     self.compilers.LIBS = oldLibs
     self.logWrite(self.framework.restoreLog())