How to understand the output when call MPI_Abort? - c

Question

I am write a simple MPI program, I am confused at the output when we call MPI_Abort.
The code is
// main.cpp
#include "mpi.h"
#include <stdlib.h>
#include <stdio.h>
int main(int argc, char **argv)
{
MPI_Init(&argc, &argv);
int x = 1;
if (x == 1)
{
MPI_Abort(MPI_COMM_WORLD, -100);
}
MPI_Finalize();
return 0;
}
I am using the follow command to compile the program.
mpic++ main.cpp
The operating system is Ubuntu 18.04
The compiler is MPICH, type mpic++ -v in terminal can obtain detailed information of compiler:
mpicxx for MPICH version 3.3a2
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 7.4.0-1ubuntu1~18.04.1' --with-bugurl=file:///usr/share/doc/gcc-7/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr --with-gcc-major-version-only --program-suffix=-7 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --with-target-system-zlib --enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 7.4.0 (Ubuntu 7.4.0-1ubuntu1~18.04.1)
If I run the executable file by the follow command
./a.out
The output is
application called MPI_Abort(MPI_COMM_WORLD, -100) - process 0
[unset]: write_line error; fd=-1 buf=:cmd=abort exitcode=-100
:
system msg for write_line failure : Bad file descriptor
How to understand the write line error? write line failure? Indeed what happens?
If I run the executable file by the follow command
mpirun -np 2 ./a.out
The output is
application called MPI_Abort(MPI_COMM_WORLD, -100) - process 0
[cli_0]: readline failed
How to understand the read line failed? Indeed what happens?
Thanks for your time.