RabbitMQ crashing on boot

[Nathan Long]

RabbitMQ has recently started crashing for me. I suspect I updated something by accident. On MacOS 10.15.7, `brew list rabbitmq` finds various files in `/usr/local/homebrew/Cellar/rabbitmq/3.8.14`.

When I try to run `rabbitmq-server` or any `rabbitmqctl` command, such as `rabbitmqctl version`, it crashes with:

```
{"init terminating in do_boot",{load_failed,[supervisor,logger_backend,logger_simple_h,logger_config,gen_event,logger_server,kernel,file_io_server,file_server,filename,file,erl_parse,erl_lint,application_controller,error_logger,lists,application,application_master,code,error_handler,logger,logger_filters,heart,gen_server,gen,ets,proc_lib,erl_eval,code_server]}}
```

Uninstalling and reinstalling has not helped.

The error is similar to the one [described here](https://groups.google.com/g/rabbitmq-users/c/O6nTPME65FA), where this was suggested:

> Some modules cannot be loaded. You very likely run a version of Erlang that's older than the oldest one supported by RabbitMQ

But according to [the docs](https://www.rabbitmq.com/which-erlang.html), RabbitMQ `3.8.14` requires Erlang `22.3` to `23.x`, and `erl --version` prints `Erlang/OTP 23`.

See [the `erl_crash.dump`](https://gist.github.com/nathanl/ae93369da2c1d3e2b05588dcfd725fee).

Any clues about what's wrong?

[Nathan Long]

FWIW I also did `brew uninstall erlang` and `brew install rabbitmq` to get a fresh install of the erlang dependency, too, but no change.

[Nathan Long]

I do use `asdf` as a version manager, so `which erl` points to `~/.asdf/shims/erl`, but my `~/.tool-versions` lists `erlang 23.1`, `asdf which erl` returns `~/.asdf/installs/erlang/23.1/bin/erl`, and `erl` prints `Erlang/OTP 23` at the top of the shell.

[Nathan Long]

I moved the config files from the previous install to another location before reinstalling, so the new install has fresh copies of `enabled_plugins` and `rabbitmq-env.conf` in `/usr/local/Homebrew/etc/rabbitmq`

[Nathan Long]

I've done `asdf uninstall` on every version of erlang but 23.1. No change.

[M K]

Something is off about the Erlang installation. A number of standard library modules cannot be loaded

(but the version is indeed 23 according to the crash dump file).

Consider uninstalling RabbitMQ *and* all Erlang versions (Homebrew-installed RabbitMQ also may pick up a version that's not Homebrew-provided, in theory).

Since Homebrew uses a binary build that you can easily run with any Erlang in PATH, you can try without Homebrew [1].

`kerl` [2] is a trivial way to build any Erlang release on macOS in case you need to do it, e.g. for comparison.

1. https://www.rabbitmq.com/install-generic-unix.html

2. https://github.com/kerl/kerl

[Nathan Long]

Uninstalling RabbitMQ and all Erlang versions, then doing `brew install erlang` did indeed fix it. Thank you!

[Ivan Gavran]

I had the same issue and was able to resolve it by installing Erlang with kerl and RabbitMQ without homebrew. (Just installing Erlang with kerl and reinstalling RabbitMQ with homebrew did not help).