RPM dependency on erlang

[maederm]

I have a question about using dnf to install rabbitmq. It seems that the dependencies on the rabbitmq-server only specifies erlang >= 23.2. However in the erlang repo there is already an 25.x release which isn't supported for that version of rabbitmq-server according to [1]. With the last system upgrade we run into an issue with an incompatible erlang release.
Do I have to versionlock the package? Naively I assumed that the rabbitmq-server package would specify the allowed version range of erlang.
[1] https://www.rabbitmq.com/which-erlang.html

[michaelklishin]

Erlang 25 is supported by RabbitMQ 3.10 and latest 3.9 and 3.8 patch releases run on it. You should be able to pin Erlang to a specific version if you really have to.

[maederm]

As an example, if you install rabbitmq-server with release 3.9.20 on RHEL8, you would get an incompatible erlang release. Is that intended?

To be more clear, shouldn't the package rabbitmq-server next to erlang >= 0:23.2 also have the dependency erlang <= 0:24.3?

[michaelklishin]

You do get a compatible version, we just don't list Erlang 25 as supported in the docs so that people upgrade to 3.10 at the same time.

You can pin Erlang to a specific version.

[maederm]

Fair enough, we ran into issues because of that behavior (we basically pinned Rabbitmq without the Erlang release).

rabbitmq-plugins crashed with please re-compile this module with an Erlang/OTP 25 compiler. Rabbitmq itself kept running.

[michaelklishin]

This is a known CLI tools behavior that's been addressed in 3.9.19 or so.