Eksperimental

These are the contents of `_redirects` ``` ## Redirects to erlang.org /download/* https://erlang.org/download/:splat /~* https://erlang.org/~:splat /course/* https://erlang.org/course/:splat /documentation/* https://erlang.org/documentation/:splat /mailman/* https://erlang.org/mailman/:splat /mailman-icons/* https://erlang.org/mailman-icons/:splat /pipermail/* https://erlang.org/pipermail/:splat ## Old removed URLs /doc/search...

What I will do is replace now that the links are standardized , replace `https://www.erlang.org/` with `/` when go over the redirect rules and find (/download|/course) etc and prefix them...

Once done we can run a link checker throughout the site and find broken links and fix them manually.

Removing the spec or replacing it with `@spec foo(term) :: pos_integer()` emits no warning.

Maybe I oversimplified the example. I will try to analyze the real case I had and get back with more info. Thank you @erszcz

Here's an updated example that fails ```elixir defmodule Unreacheable do @spec foo(term) :: {:ok, term} | :error def foo(bar) do with pid when is_pid(pid) nil 2 -> self() end end...

This one is even more simplified. ```elixir defmodule Unreacheable do require Integer @spec the_odds(term) :: {:even | :odd, pos_integer()} def the_odds(bar) do with integer when Integer.is_odd(integer)

Converting the latter example to generated Erlang code, and back to Elixir, it looks like this. ```elixir defmodule UnreacheableExpanded do require Integer import Bitwise @spec the_odds(term) :: {:even | :odd,...

The warning will be gone when Elixir supports OTP25+ exclusively as it's planned to port `with` to use the recently introduced `maybe` in Erlang. https://www.erlang.org/doc/reference_manual/expressions.html#maybe

I have investigated it and tracked down what is causing this, it is reported in #129.