Deprecation warnings on a brand new project: warning: Plug.Conn.WrapperError.reraise/3 is deprecated

On a brand new project, created with “mix”, I get this when I compile…

@eric ➜ mpv2  mix compile
Compiling 13 files (.ex)
warning: Plug.Conn.WrapperError.reraise/3 is deprecated. Use reraise/1 or reraise/4 instead.
Found at 2 locations:

Generated mpv2 app
@eric ➜ mpv2  mix --version
Erlang/OTP 20 [erts-9.3] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:10] [kernel-poll:false]

Mix 1.6.3 (compiled with OTP 19)
@eric ➜ mpv2  elixir --version
Erlang/OTP 20 [erts-9.3] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:10] [kernel-poll:false]

Elixir 1.6.3 (compiled with OTP 19)

Is this correct, expected, can I ignore it, how do I remedy it etc?


This is due to a recent change in Plug:

My best guess is that phoenix hasn’t quite caught up with this change. It’s just a deprecation, so I would assume you can ignore it and that it will most likely be fixed in the next Phoenix version.


Thank you , I figured it was OK but it’s not what you expect to see on a freshly minted project, starting out with compiler warnings before you even write a line of your won code but given the amount of behind-the-scenes code dependencies it’s too be expected from time to time I guess.

It’s still the best system to be using, ever!

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Alternatively, you can just lock plug to 1.5.0 in mix.exs:

{:plug, "1.5.0"}