The following bug has been logged on the website:
Bug reference: 16598
Logged by: Oliver Yang
Email address: oliver_hom(at)yahoo(dot)com
PostgreSQL version: 12.4
Operating system: Ubuntu
Description:
Inside SharedFileSetCreate, it tries to create the shared temp file in one
of its temp table space. If it fails, it creates the temp directory on
demand and then retries temp file creation again. However, the temp table
space used in temp directory creation and temp file creation can be
different, which might result in false negative in SharedFileSetCreate.