test_io_shared: Test again

Author: eschnett

.github/workflows/UnitTests.yml

@@ -556,6 +556,8 @@ jobs:
       MV2_SMP_USE_CMA: 0
       # Work around issue with affinity not set.  Ref:
       # https://github.com/JuliaParallel/MPI.jl/pull/810#issuecomment-1920255386
+      # MVAPICH 2 and 3 use different environment variables; set both.
+      MV2_ENABLE_AFFINITY: 0
       MVP_ENABLE_AFFINITY: 0
 
     steps:

test/test_io_shared.jl

@@ -48,7 +48,7 @@ sync()
 #TODO # https://github.com/JuliaParallel/MPI.jl/issues/555,
 #TODO # https://github.com/JuliaParallel/MPI.jl/issues/579
 #TODO @test MPI.File.get_position_shared(fh) == sum(1:sz) skip = Sys.isapple() || Sys.iswindows()
-# TODO: still broken on Apple
+# TODO: still broken on Apple with MPICH
 @test MPI.File.get_position_shared(fh) == sum(1:sz)
 
 MPI.File.seek_shared(fh, 0)
@@ -63,6 +63,7 @@ sync()
 #TODO # TODO: this has to be fixed:
 #TODO # https://github.com/JuliaParallel/MPI.jl/issues/555
 #TODO @test MPI.File.get_position_shared(fh) == sum(1:sz) skip = Sys.iswindows()
+# TODO: still broken on Windows with MPICH
 @test MPI.File.get_position_shared(fh) == sum(1:sz)
 
 MPI.File.set_view!(fh, 0, MPI.Datatype(UInt8), MPI.Datatype(UInt8))