Getting FunctionClauseError from Ecto.Adapters.SQL.Sandbox.Pool.disconnect/4 in Ecto 2.0.1

[myronmarston]

Environment

• Elixir version (elixir -v):

Erlang/OTP 18 [erts-7.3] [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false] [dtrace]

Elixir 1.3.0

• Database and version (PostgreSQL 9.4, MongoDB 3.2, etc.):

MySQL Server version: 5.6.25-73.1 Homebrew

• Ecto version (mix deps):

  "ecto": {:hex, :ecto, "2.0.1", "cf97a4d353e14af3d3cc3b4452cfbd18b3aeee1fb4075475efeccec3853444a9", [:mix], [{:poison, "~> 1.5 or ~> 2.0", [hex: :poison, optional: true]}, {:sbroker, "~> 1.0-beta", [hex: :sbroker, optional: true]}, {:mariaex, "~> 0.7.7", [hex: :mariaex, optional: true]}, {:postgrex, "~> 0.11.2", [hex: :postgrex, optional: true]}, {:db_connection, "~> 1.0-rc.2", [hex: :db_connection, optional: true]}, {:decimal, "~> 1.0", [hex: :decimal, optional: false]}, {:poolboy, "~> 1.5", [hex: :poolboy, optional: false]}]},

• Database adapter and version (mix deps):

  "mariaex": {:hex, :mariaex, "0.7.7", "620a636ec2276c3fa031ac528039fc9d2bf7992e050e37a56b3c796511e94d6d", [:mix], [{:db_connection, "~> 1.0.0-rc", [hex: :db_connection, optional: false]}, {:decimal, "~> 1.0", [hex: :decimal, optional: false]}]},

• Operating system:

OS X El Capitan

Current behavior

In my tests, I periodically get this error:

     ** (exit) exited in: GenServer.call(#PID<0.21338.0>, {:checkout, #Reference<0.0.1.249038>, true, 15000}, 5000)
         ** (EXIT) an exception was raised:
             ** (FunctionClauseError) no function clause matching in Ecto.Adapters.SQL.Sandbox.Pool.disconnect/4
                 (ecto) lib/ecto/adapters/sql/sandbox.ex:371: Ecto.Adapters.SQL.Sandbox.Pool.disconnect({#PID<0.2872.0>, #PID<0.2875.0>, {#PID<0.2875.0>, #Reference<0.0.1.248995>}}, %DBConnection.ConnectionError{message: "client #PID<0.21347.0> exited with: no process"}, {Mariaex.Protocol, %Mariaex.Protocol{buffer: "", cache: 9166937, catch_eof: false, connection_id: #PID<0.2875.0>, connection_ref: #Reference<0.0.2.15580>, lru_cache: {100, 9171034}, opts: [socket_options: [], sock_type: :tcp, cache_size: 100, pool: DBConnection.Poolboy, otp_app: :legion, repo: Delorean.Legion.Shard0Repo, adapter: Ecto.Adapters.MySQL, hostname: "127.0.0.1", database: "legion_shard_0_test", username: "root", password: nil, pool_timeout: 5000, timeout: 15000, adapter: Ecto.Adapters.MySQL, port: 3306], protocol57: false, rows: [], seqnum: 0, sock: {Mariaex.Connection.Tcp, #Port<0.44114>}, state: :running, state_data: {0, 0}, timeout: 15000}, false}, [timeout: :infinity, repo: Delorean.Legion.Shard0Repo, sandbox_pool: DBConnection.Poolboy, ownership_pool: Ecto.Adapters.SQL.Sandbox.Pool, pool_timeout: 5000, adapter: Ecto.Adapters.MySQL, pool: DBConnection.Ownership])
                 (db_connection) lib/db_connection/ownership/proxy.ex:242: DBConnection.Ownership.Proxy.disconnect/2
                 (stdlib) gen_server.erl:615: :gen_server.try_dispatch/4
                 (stdlib) gen_server.erl:681: :gen_server.handle_msg/5
                 (stdlib) proc_lib.erl:240: :proc_lib.init_p_do_apply/3
     stacktrace:
       (db_connection) lib/db_connection/ownership/proxy.ex:32: DBConnection.Ownership.Proxy.checkout/2
       (db_connection) lib/db_connection.ex:716: DBConnection.checkout/2
       (db_connection) lib/db_connection.ex:623: DBConnection.run/3
       (db_connection) lib/db_connection.ex:464: DBConnection.prepare_execute/4
       (ecto) lib/ecto/adapters/mysql/connection.ex:32: Ecto.Adapters.MySQL.Connection.execute/4
       (ecto) lib/ecto/adapters/sql.ex:228: Ecto.Adapters.SQL.sql_call/6
       (ecto) lib/ecto/adapters/sql.ex:178: Ecto.Adapters.SQL.query!/5

It works when I retry, so I can't consistently reproduce.

Expected behavior

The error should not happen, unless it's due to some problem I'm not aware of with how we are using Ecto in our tests -- in which case, it should give me an error explaining what I'm doing wrong.

[josevalim]

It is already fixed in master and I just pushed a test, thank you! :)