InitError on Julia 1.3 with system MPI

[jipolanco]

For some reason that I don't really understand, MPI.jl 0.17 throws an InitError when loaded using Julia 1.3 on Unix (or at least Linux) systems, when using the system MPI libraries.

See here for an example, that I have also reproduced locally on Fedora 33. I also tested on Julia 1.5, 1.6 and nightly, where the issue does not appear.

The issue seems to be related to #451. The problem is that ccall does not seem to find MPI_Get_library_version. I managed to workaround the issue by adding an exception for this specific function in the @mpicall macro.

My workaround can be seen here, and I can open a PR if this is a proper solution.

Here is a minimum example:

➜  MPI git:(master) ~/opt/julia-1.3/bin/julia --project -e 'using MPI'
ERROR: InitError: ccall: could not find function MPI_Get_library_version
Stacktrace:
 [1] Get_library_version() at /home/jipolanco/.julia/dev/MPI/src/implementations.jl:36
 [2] __init__deps() at /home/jipolanco/.julia/dev/MPI/deps/deps.jl:11
 [3] __init__() at /home/jipolanco/.julia/dev/MPI/src/MPI.jl:67
 [4] _include_from_serialized(::String, ::Array{Any,1}) at ./loading.jl:692
 [5] _require_from_serialized(::String) at ./loading.jl:743
 [6] _require(::Base.PkgId) at ./loading.jl:1034
 [7] require(::Base.PkgId) at ./loading.jl:922
 [8] require(::Module, ::Symbol) at ./loading.jl:917
during initialization of module MPI

[simonbyrne]

I'm not sure why that would happen, but I'm happy to accept a PR if you need Julia 1.3 support.