They are leak check warnings. They indicate not all datatype handles are freed (via MPI_Type_free). We understand not all users care about these handle leaks, thus this warning will be disabled by default in the next release. -- Hui Zhou From: Mccall, Kurt E. (MSFC-EV41) via discuss <[email protected]> Date: Tuesday, July 23, 2024 at 11:08 AM To: [email protected] <[email protected]> Cc: Mccall, Kurt E. (MSFC-EV41) <[email protected]> Subject: [mpich-discuss] yaksa: leaked handle pool objects In my MPICH 4. 1. 2 application, I am getting a few of these warnings, when MPI_Finalize is called. [WARNING] yaksa: 2 leaked handle pool objects Is there any way to tell where/why they are occurring? Thanks, Kurt . ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ZjQcmQRYFpfptBannerStart This Message Is From an External Sender This message came from outside your organization. ZjQcmQRYFpfptBannerEnd In my MPICH 4.1.2 application, I am getting a few of these warnings, when MPI_Finalize is called. [WARNING] yaksa: 2 leaked handle pool objects Is there any way to tell where/why they are occurring? Thanks, Kurt .