It sounds like your use case is going beyond running your elixir tests and the specific need of being able to diagnose a specific test failure.

That said, if you must “copy it and do other things with it as well”, then simply force commit the transaction from IEx.pry by typing something like Ecto.Adapters.SQL.query!(MyApp.Repo, "COMMIT") to preserve the transaction in the database and then exit iex and then you can copy the database and do all those other things you want.

Not entirely true. Transactions certainly do work in SQLite. With how ecto does sandbox rollbacks, things get a little weird. As long as your journal mode is set to WAL and the filesystem that the system is running on is not an NFS mount, it should work just fine.

You could run your tests in iex and use IEx.pry to inspect things.

This is not a mode of working that I use but here are some posts that explains how to start tests with iex and use IEx.pry:

• Debugging · Elixir School
• How to Use IEx.pry in Elixir Tests - Elixir Tutorials