Underlying Ecto errors not propagated (?): ** (RuntimeError) could not lookup Ecto repo X.Y because it was not started or it does not exist

Can you show the complete logs from system boot to that point?

Yes, thanks! You’ll see we also get these other errors/warnings with that dataset only:

robb@arbor ~/s/M/phoenix (master) [1]> mix test
13:15:43.764 [error] Postgrex.Protocol (#PID<0.547.0>) disconnected: ** (DBConnection.ConnectionError) #PID<0.90.0> checked in the connection owned by #PID<0.621.0>

#PID<0.90.0> triggered the checkin at location:

    (kernel) code_server.erl:140: :code_server.call/1
    (elixir) src/elixir_compiler.erl:80: :elixir_compiler.dispatch/4
    (elixir) src/elixir_compiler.erl:63: :elixir_compiler.compile/3
    (elixir) src/elixir_lexical.erl:17: :elixir_lexical.run/2
    (elixir) src/elixir_compiler.erl:23: :elixir_compiler.quoted/2
    (elixir) lib/code.ex:767: Code.require_file/2
    (elixir) lib/enum.ex:769: Enum."-each/2-lists^foreach/1-0-"/2
    (elixir) lib/enum.ex:769: Enum.each/2


Client #PID<0.621.0> is still using a connection from owner at location:

    :prim_inet.ctl_cmd/3
    :prim_inet.async_recv/3
    :prim_inet.recv0/3
    (postgrex) lib/postgrex/protocol.ex:2879: Postgrex.Protocol.rows_recv/5
    (postgrex) lib/postgrex/protocol.ex:1898: Postgrex.Protocol.recv_execute/5
    (postgrex) lib/postgrex/protocol.ex:1772: Postgrex.Protocol.bind_execute/4
    (db_connection) lib/db_connection/holder.ex:293: DBConnection.Holder.holder_apply/4
    (db_connection) lib/db_connection.ex:1255: DBConnection.run_execute/5

The connection itself was checked out by #PID<0.621.0> at location:

    (ecto_sql) lib/ecto/adapters/sql.ex:570: Ecto.Adapters.SQL.execute!/4


13:15:43.810 [error] GenServer #PID<0.621.0> terminating
** (DBConnection.ConnectionError) tcp recv: closed (the connection was closed by the pool, possibly due to a timeout or because the pool has been terminated)
    (ecto_sql) lib/ecto/adapters/sql.ex:629: Ecto.Adapters.SQL.raise_sql_call_error/1
    (ecto_sql) lib/ecto/adapters/sql.ex:562: Ecto.Adapters.SQL.execute/5
    (ecto) lib/ecto/repo/queryable.ex:177: Ecto.Repo.Queryable.execute/4
    (ecto) lib/ecto/repo/queryable.ex:17: Ecto.Repo.Queryable.all/3
    (macrostax) lib/macrostax/accounts/signup_worker.ex:31: Macrostax.Accounts.SignupWorker.check_abandoned/0
    (macrostax) lib/macrostax/accounts/signup_worker.ex:23: Macrostax.Accounts.SignupWorker.handle_info/2
    (stdlib) gen_server.erl:637: :gen_server.try_dispatch/4
    (stdlib) gen_server.erl:711: :gen_server.handle_msg/6
Last message: :check_abandoned
13:15:43.893 [error] GenServer #PID<0.669.0> terminating
** (DBConnection.OwnershipError) cannot find ownership process for #PID<0.669.0>.

When using ownership, you must manage connections in one
of the four ways:

* By explicitly checking out a connection
* By explicitly allowing a spawned process
* By running the pool in shared mode
* By using :caller option with allowed process

The first two options require every new process to explicitly
check a connection out or be allowed by calling checkout or
allow respectively.

The third option requires a {:shared, pid} mode to be set.
If using shared mode in tests, make sure your tests are not
async.

The fourth option requires [caller: pid] to be used when
checking out a connection from the pool. The caller process
should already be allowed on a connection.

If you are reading this error, it means you have not done one
of the steps above or that the owner process has crashed.

See Ecto.Adapters.SQL.Sandbox docs for more information.
    (ecto_sql) lib/ecto/adapters/sql.ex:626: Ecto.Adapters.SQL.raise_sql_call_error/1
    (ecto_sql) lib/ecto/adapters/sql.ex:562: Ecto.Adapters.SQL.execute/5
    (ecto) lib/ecto/repo/queryable.ex:177: Ecto.Repo.Queryable.execute/4
    (ecto) lib/ecto/repo/queryable.ex:17: Ecto.Repo.Queryable.all/3
    (macrostax) lib/macrostax/accounts/signup_worker.ex:31: Macrostax.Accounts.SignupWorker.check_abandoned/0
    (macrostax) lib/macrostax/accounts/signup_worker.ex:23: Macrostax.Accounts.SignupWorker.handle_info/2
    (stdlib) gen_server.erl:637: :gen_server.try_dispatch/4
    (stdlib) gen_server.erl:711: :gen_server.handle_msg/6
Last message: :check_abandoned
13:15:43.894 [error] GenServer #PID<0.671.0> terminating
** (DBConnection.OwnershipError) cannot find ownership process for #PID<0.671.0>.

When using ownership, you must manage connections in one
of the four ways:

* By explicitly checking out a connection
* By explicitly allowing a spawned process
* By running the pool in shared mode
* By using :caller option with allowed process

The first two options require every new process to explicitly
check a connection out or be allowed by calling checkout or
allow respectively.

The third option requires a {:shared, pid} mode to be set.
If using shared mode in tests, make sure your tests are not
async.

The fourth option requires [caller: pid] to be used when
checking out a connection from the pool. The caller process
should already be allowed on a connection.

If you are reading this error, it means you have not done one
of the steps above or that the owner process has crashed.

See Ecto.Adapters.SQL.Sandbox docs for more information.
    (ecto_sql) lib/ecto/adapters/sql.ex:626: Ecto.Adapters.SQL.raise_sql_call_error/1
    (ecto_sql) lib/ecto/adapters/sql.ex:562: Ecto.Adapters.SQL.execute/5
    (ecto) lib/ecto/repo/queryable.ex:177: Ecto.Repo.Queryable.execute/4
    (ecto) lib/ecto/repo/queryable.ex:17: Ecto.Repo.Queryable.all/3
    (macrostax) lib/macrostax/accounts/signup_worker.ex:31: Macrostax.Accounts.SignupWorker.check_abandoned/0
    (macrostax) lib/macrostax/accounts/signup_worker.ex:23: Macrostax.Accounts.SignupWorker.handle_info/2
    (stdlib) gen_server.erl:637: :gen_server.try_dispatch/4
    (stdlib) gen_server.erl:711: :gen_server.handle_msg/6
Last message: :check_abandoned
13:15:43.894 [error] GenServer #PID<0.672.0> terminating
** (DBConnection.OwnershipError) cannot find ownership process for #PID<0.672.0>.

When using ownership, you must manage connections in one
of the four ways:

* By explicitly checking out a connection
* By explicitly allowing a spawned process
* By running the pool in shared mode
* By using :caller option with allowed process

The first two options require every new process to explicitly
check a connection out or be allowed by calling checkout or
allow respectively.

The third option requires a {:shared, pid} mode to be set.
If using shared mode in tests, make sure your tests are not
async.

The fourth option requires [caller: pid] to be used when
checking out a connection from the pool. The caller process
should already be allowed on a connection.

If you are reading this error, it means you have not done one
of the steps above or that the owner process has crashed.

See Ecto.Adapters.SQL.Sandbox docs for more information.
    (ecto_sql) lib/ecto/adapters/sql.ex:626: Ecto.Adapters.SQL.raise_sql_call_error/1
    (ecto_sql) lib/ecto/adapters/sql.ex:562: Ecto.Adapters.SQL.execute/5
    (ecto) lib/ecto/repo/queryable.ex:177: Ecto.Repo.Queryable.execute/4
    (ecto) lib/ecto/repo/queryable.ex:17: Ecto.Repo.Queryable.all/3
    (macrostax) lib/macrostax/accounts/signup_worker.ex:31: Macrostax.Accounts.SignupWorker.check_abandoned/0
    (macrostax) lib/macrostax/accounts/signup_worker.ex:23: Macrostax.Accounts.SignupWorker.handle_info/2
    (stdlib) gen_server.erl:637: :gen_server.try_dispatch/4
    (stdlib) gen_server.erl:711: :gen_server.handle_msg/6
Last message: :check_abandoned
Excluding tags: [:skip, :hits_external_api]

.......

  1) test migrate_food/1 given a simple meal: creates Recipes, Foods, Conversions, and Tags with expected hierarchy (Macrostax.Utils.KitchenSchemaMigratorTest)
     test/macrostax/utils/kitchen_schema_migrator_test.exs:17
     ** (RuntimeError) could not lookup Ecto repo Macrostax.Repo because it was not started or it does not exist
     stacktrace:
       (ecto) lib/ecto/repo/registry.ex:19: Ecto.Repo.Registry.lookup/1
       (ecto) lib/ecto/adapter.ex:127: Ecto.Adapter.lookup_meta/1
       (ecto_sql) lib/ecto/adapters/sql/sandbox.ex:487: Ecto.Adapters.SQL.Sandbox.lookup_meta!/1
       (ecto_sql) lib/ecto/adapters/sql/sandbox.ex:415: Ecto.Adapters.SQL.Sandbox.checkout/2
       (macrostax) test/support/data_case.ex:30: Macrostax.DataCase.__ex_unit_setup_0/1
       (macrostax) test/support/data_case.ex:1: Macrostax.DataCase.__ex_unit__/2
       test/macrostax/utils/kitchen_schema_migrator_test.exs:1: Macrostax.Utils.KitchenSchemaMigratorTest.__ex_unit__/2

After resetting the test db, we don’t get warnings about the code. Instead, it’s just all green:

robb@arbor ~/s/M/phoenix (master)> mix test
Excluding tags: [:skip, :hits_external_api]

..........................................................................................................................

Finished in 12.3 seconds
142 tests, 0 failures, 20 excluded

Randomized with seed 149348

This is helpful thanks. As one more thing can you mix deps|grep ecto and mix deps|grep postgrex?

Thanks - maybe it’s been too long since we’ve updated?

robb@arbor ~/s/M/phoenix (master)> mix deps|grep ecto
* ecto 3.2.5 (Hex package) (mix)
  locked at 3.2.5 (ecto) 01251d9b
* ecto_sql 3.2.1 (Hex package) (mix)
  locked at 3.2.1 (ecto_sql) 4790973b
* ecto_enum 1.4.0 (Hex package) (mix)
  locked at 1.4.0 (ecto_enum) 8fb55c08
* scrivener_ecto 2.2.0 (Hex package) (mix)
  locked at 2.2.0 (scrivener_ecto) 3eadfc0a
* timber_ecto 2.1.1 (Hex package) (mix)
  locked at 2.1.1 (timber_ecto) 4adc8e60
* phoenix_ecto 4.1.0 (Hex package) (mix)
  locked at 4.1.0 (phoenix_ecto) c5e666a3
robb@arbor ~/s/M/phoenix (master)> mix deps|grep postgrex
* postgrex 0.15.1 (Hex package) (mix)
  locked at 0.15.1 (postgrex) 12cd418e
robb@arbor ~/s/M/phoenix (master)> elixir --version
Erlang/OTP 21 [erts-10.1] [source] [64-bit] [smp:16:16] [ds:16:16:10] [async-threads:1] [hipe]

Elixir 1.8.1 (compiled with Erlang/OTP 20)