I've been experimenting with moving the Unix socket directory to /var/run/postgresql for the Fedora distribution (don't ask :-(). It's mostly working, but I found out yet another way that pg_upgrade can crash and burn: it doesn't consider the possibility that the old or new postmaster is compiled with a different default unix_socket_directory than what is compiled into the libpq it's using or that pg_dump is using.
This is another hazard that we could forget about if we had some way for pg_upgrade to run standalone backends instead of starting a postmaster. But in the meantime, I suggest it'd be a good idea for pg_upgrade to explicitly set unix_socket_directory (or unix_socket_directories in HEAD) when starting the postmasters, and also explicitly set PGHOST to ensure that the client-side code plays along. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers