Hello Laurenz, thanks for your quick reply.
The issue was having the old postgres library in LD_LIBRARY_PATH. Once I removed it, everything started to look good! In all the past years this was not a problem though. But anyway: All good now!
Thanks again: peter
On 20 Jun 2025, at 14:00, Laurenz Albe <laurenz.albe@cybertec.at> wrote:
On Fri, 2025-06-20 at 13:49 +0200, Peter Röthlisberger wrote:
Hello all,
Platform: Rocky Linux release 9.4 (Blue Onyx)
I try to migrate from version 16.7 to 17.5. When executing pg_upgrade —check I get the following:
could not load library "$libdir/dblink": ERROR: could not load library "/opt/postgresql-17.5/lib/dblink.so": /opt/postgresql-17.5/lib/dblink.so: undefined symbol: PQcancelStart
In database: zen_dev1
In database: zen_prod2
could not load library "$libdir/postgres_fdw": ERROR: could not load library "/opt/postgresql-17.5/lib/postgres_fdw.so": /opt/postgresql-17.5/lib/postgres_fdw.so: undefined symbol: PQcancelStart
In database: zen_dev1
I tried hard to find a hint on the net. No success hence my first post here. I was able to execute the update on another server having the same OS.
How did you install "dblink.so" and "postgres_fdw.so"?
It looks like you copied them from the old installation. That won't work.
Yours,
Laurenz Albe
Peter Roethlisberger
Senior System & Database Architect
Zen Innovations AG
Bernstrasse 99
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Phone: +41 (0)31 550 07 65
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peter.roethlisberger@zen-innovations.com
