Can't build Phoenix project after Elixir and hex update

Question

i have updated yesterday my Elixir to newest version and hex to 0.10.4 Since then I am getiing all kinds of errors while trying to run my app which was working good enough earlier.

Here are logs:

==> postgrex
Compiled lib/postgrex/binary_extension.ex
Compiled lib/postgrex/app.ex
Compiled lib/postgrex/binary_utils.ex
Compiled lib/postgrex/extension.ex
Compiled lib/postgrex/extensions/bool.ex
Compiled lib/postgrex/extensions/date.ex
Compiled lib/postgrex/error.ex
Compiled lib/postgrex/extensions/float4.ex
Compiled lib/postgrex/error_code.ex
Compiled lib/postgrex/extensions/array.ex
Compiled lib/postgrex/extensions/int2.ex
Compiled lib/postgrex/extensions/int4.ex
Compiled lib/postgrex/extensions/float8.ex
Compiled lib/postgrex/extensions/int8.ex
Compiled lib/postgrex/extensions/hstore.ex
Compiled lib/postgrex/extensions/json.ex
Compiled lib/postgrex/extensions/interval.ex
Compiled lib/postgrex/extensions/raw.ex
Compiled lib/postgrex/extensions/oid.ex
Compiled lib/postgrex/extensions/network.ex
Compiled lib/postgrex/extensions/macaddr.ex
Compiled lib/postgrex/builtins.ex
Compiled lib/postgrex/extensions/point.ex
Compiled lib/postgrex/extensions/tid.ex
Compiled lib/postgrex/extensions/record.ex
Compiled lib/postgrex/extensions/range.ex
Compiled lib/postgrex/extensions/numeric.ex
Compiled lib/postgrex/extensions/void.ex
Compiled lib/postgrex/extensions/uuid.ex
Compiled lib/postgrex/extensions/time.ex
Compiled lib/postgrex/extensions/timestamp.ex
Compiled lib/postgrex/result.ex
Compiled lib/postgrex/type_info.ex
Compiled lib/postgrex/utils.ex
Compiled lib/postgrex/type_server.ex
Compiled lib/postgrex.ex
Compiled lib/postgrex/parameters.ex
Compiled lib/postgrex/notifications.ex
Compiled lib/postgrex/query.ex
Compiled lib/postgrex/types.ex
Compiled lib/postgrex/messages.ex

== Compilation error on file lib/postgrex/protocol.ex ==
** (CompileError) lib/postgrex/protocol.ex:61: Postgrex.Protocol.__struct__/0 is undefined, cannot expand struct Postgrex.Protocol
    (elixir) src/elixir_map.erl:58: :elixir_map.translate_struct/4

Can't really decide whether i have done something wrong.

Mix hex.info:

Hex:    0.10.4
Elixir: 1.2.3
OTP:    18.0

Built with: Elixir 1.2.1 and OTP 18.2.2

Registry file available (last updated: 2016-02-29 18:02:10)
Size: 1541kB (compressed 501kb)
Packages #: 1626
Versions #: 7211

Answer 1

For the reference of anyone else who might run across this question and want to know what to do--Try removing the _build directory (via @asonge and @MichealJohnston above).

Marking this answer as community wiki since it's not my answer.