Error installing Erlang 23.1.1 on MacOS.

[weaversam8]

I encountered a variant of #157 while installing Erlang 23.1.1. It manifested as the following symptoms:

• The install seemingly hung mid installation, but pressing Enter caused the installation to proceed
• The error from Unable to install on macOS: 'in6addr_any' follows non-static declaration #157 ('in6addr_any' follows non-static declaration) was encountered.

I tried running with KERL_DEBUG=1 and saw the same behavior. But, on a failed install, it suggested I check the log at ~/.asdf/plugins/erlang/kerl-home/builds/asdf_23.1.1/otp_build_23.1.1.log. I opened this file, and the same error appeared.

When I attempted to install again, the file was overwritten, but when the build hung, I saw the reason in the log file. patch was waiting for an interactive input:

Reversed (or previously applied) patch detected!  Assume -R? [y]

If I typed n, Enter, I got this message:

Apply anyway? [n]

Then I pressed n, Enter. This allowed the installation to proceed.

I'm not sure what's broken here, but it appears that Kerl is trying to patch something that's already been patched, and is reversing it instead.

Edit: I believe I also followed the steps in this comment earlier: #195 (comment)