fix mpiexec

Author: simonbyrne

lib/MPIPreferences/src/MPIPreferences.jl

@@ -19,6 +19,7 @@ else
 end
 
 module System
+    export libmpi, mpiexec
     using Preferences
     const libmpi = @load_preference("libmpi")
     const mpiexec_path = @load_preference("mpiexec")

src/environment.jl

@@ -21,10 +21,7 @@ hello world
 hello world
 ```
 """
-function mpiexec(fn)
-    _mpiexec(cmd -> fn(`$cmd $(Base.shell_split(get(ENV, "JULIA_MPIEXEC_ARGS", "")))`))
-end
-
+mpiexec
 
 # Administrative functions
 function _warn_if_wrong_mpi()