Store full path of libmpi and mpiexec in deps.jl

This makes it slightly easier to use on clusters since it avoids the need to "module load mpiXXX" each time it is used, and makes it more robust if the wrong MPI library is loaded.

Author: simonbyrne

deps/build.jl

@@ -38,14 +38,17 @@ end
 const libmpi = find_library(Sys.iswindows() ? "msmpi.dll" : "libmpi",
                             MPI_LIBRARY_PATH !== nothing ? [MPI_LIBRARY_PATH] : [])
 
-libptr = dlopen_e(libmpi)
-if libmpi == "" || libptr == C_NULL
-    error("No MPI library found")
+if libmpi == ""
+    error("No MPI library found.\nEnsure an MPI implementation is loaded, or set the `JULIA_MPI_PATH` variable.")
 end
-@info "Using MPI library $libmpi"
 
-libpath = dlpath(libptr)
-libsize = filesize(libpath)
+# expand paths
+libmpi = dlpath(libmpi)
+libsize = filesize(libmpi)
+
+mpiexec = Sys.which(mpiexec)
+
+@info "Using MPI library $libmpi"
 
 function Get_version()
     major = Ref{Cint}()

deps/gen_consts.jl

@@ -104,6 +104,7 @@ MPI_pointers = [
     :MPI_STATUSES_IGNORE,
     ]
 
+const libptr = dlopen_e(libmpi)
 
 open("gen_consts.c","w") do f
     print(f,"""