[Bug]: pg_upgrade fails for pg 14.12 to 16.3 both on timescale 2.15.3

[cbergmiller]

What type of bug is this?

Unexpected error

What subsystems and features are affected?

Other

What happened?

I tried to run pg_upgrade to migrate from Postgres 14 to Postgres 16. Before upgrading Postgres I migrated to the latest Timescale version on the existing Postgres 14 server. It fails with the message could not load library "$libdir/timescaledb-2.15.3": ERROR: attempt to redefine parameter "timescaledb.enable_deprecation_warnings"

Installed Postgres and Timescale packages:

postgresql-14-pgpool2/bullseye-pgdg,now 4.5.2-1.pgdg110+1 amd64 [installed]
postgresql-14/bullseye-pgdg,now 14.12-1.pgdg110+1 amd64 [installed]
postgresql-16/bullseye-pgdg,now 16.3-1.pgdg110+1 amd64 [installed]
postgresql-client-14/bullseye-pgdg,now 14.12-1.pgdg110+1 amd64 [installed,automatic]
postgresql-client-16/bullseye-pgdg,now 16.3-1.pgdg110+1 amd64 [installed,automatic]
postgresql-client-common/bullseye-pgdg,now 261.pgdg110+1 all [installed,automatic]
postgresql-common/bullseye-pgdg,now 261.pgdg110+1 all [installed]
postgresql-server-dev-14/bullseye-pgdg,now 14.12-1.pgdg110+1 amd64 [installed]

timescaledb-2-loader-postgresql-14/bullseye,now 2.15.3~debian11 amd64 [installed,automatic]
timescaledb-2-loader-postgresql-16/bullseye,now 2.15.3~debian11 amd64 [installed,automatic]
timescaledb-2-postgresql-14/bullseye,now 2.15.3~debian11 amd64 [installed]
timescaledb-2-postgresql-16/bullseye,now 2.15.3~debian11 amd64 [installed]
timescaledb-toolkit-postgresql-14/bullseye,now 1:1.18.0~debian11 amd64 [installed,automatic]
timescaledb-toolkit-postgresql-16/bullseye,now 1:1.18.0~debian11 amd64 [installed,automatic]

TimescaleDB version affected

2.15.3

PostgreSQL version used

14.12, 16.3

What operating system did you use?

Debian 11

What installation method did you use?

Deb/Apt

What platform did you run on?

On prem/Self-hosted

Relevant log output and stack trace

postgres@dev-debian-2:/tmp$ /usr/lib/postgresql/16/bin/pg_upgrade -d /etc/postgresql/14/main -D /etc/postgresql/16/main -b /usr/lib/postgresql/14/bin -B /usr/lib/postgresql/16/bin
Finding the real data directory for the source cluster        ok
Finding the real data directory for the target cluster        ok
Performing Consistency Checks
-----------------------------
Checking cluster versions                                     ok
Checking database user is the install user                    ok
Checking database connection settings                         ok
Checking for prepared transactions                            ok
Checking for system-defined composite types in user tables    ok
Checking for reg* data types in user tables                   ok
Checking for contrib/isn with bigint-passing mismatch         ok
Checking for incompatible "aclitem" data type in user tables  ok
Creating dump of global objects                               ok
Creating dump of database schemas
                                                              ok
Checking for presence of required libraries                   fatal

Your installation references loadable libraries that are missing from the
new installation.  You can add these libraries to the new installation,
or remove the functions using them from the old installation.  A list of
problem libraries is in the file:
    /var/lib/postgresql/16/main/pg_upgrade_output.d/20240704T080136.575/loadable_libraries.txt
Failure, exiting

could not load library "$libdir/timescaledb-2.15.3": ERROR:  attempt to redefine parameter "timescaledb.enable_deprecation_warnings"

How can we reproduce the bug?

/usr/lib/postgresql/16/bin/pg_upgrade -d /etc/postgresql/14/main -D /etc/postgresql/16/main -b /usr/lib/postgresql/14/bin -B /usr/lib/postgresql/16/bin