Bug in CO_SUM (and most likely, other collective intrinsic subroutines).

[OP1]

CO_SUM does not return STAT = 0 when its execution is successful - it simply preserves whatever value STAT had prior to its call!

You can see this by commenting/uncommenting line 7 in the code below.

The code was compiled with IFX2025.1.0.

PROGRAM P
IMPLICIT NONE

INTEGER :: S, STAT
CHARACTER(LEN = 20) :: MESSAGE

!STAT = 0
S = THIS_IMAGE()
CALL CO_SUM(S, STAT = STAT, ERRMSG = MESSAGE)
IF (STAT /= 0) THEN
    WRITE(*, *) S, THIS_IMAGE(), STAT, MESSAGE
END IF

END

[taehunkim]

Hi,

We found an error and started triaging it with development team.

Thanks.