Simple hello world fails to launch correctly

[dmarce1]

Expected Behavior

From this example code:

#include <hpx/hpx_init.hpp>
int hpx_main(int argc, char* argv[]) {
	printf( "Hello World!\n");
	return hpx::finalize();
}
int main(int argc, char* argv[]) {
	hpx::init(argc, argv);
}

I expect there to be one instance of hpx_main called and the output to be:

Hello World!

Actual Behavior

When run with mpirun -np 2, the output is

Hello World!
Hello World!

Steps to Reproduce the Problem

I compiled the above code using cmake file:

project(hello CXX)
find_package(HPX REQUIRED NO_CMAKE_PACKAGE_REGISTRY)

add_hpx_executable(
  hello
  DEPENDENCIES
  SOURCES
    main.cpp
)

and executed it with mpirun -np 2 ./hello

Specifications

... Please describe your environment

• HPX Version: Top of master
• Platform (compiler, OS): GNU 8.2 Ubuntu 18.04

[hkaiser]

@dmarce1 Was HPX built with MPI enabled?

[dmarce1]

Yes

[hkaiser]

Please see #4035 for a possible solution and let us know if this fixes your issue.

[dmarce1]

This fixes it. Thanks.