multiple defaults bug

[kmc-firework]

Elixir and Erlang/OTP versions

first noticed in elixir 1.17 but reproduced in most recent build too:

Erlang/OTP 28 [erts-16.1] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [jit]

Elixir 1.19.0-rc.0 (8d216b8) (compiled with Erlang/OTP 26)

Operating system

MacOS 15.6.1

Current behavior

 mix compile
Compiling 1 file (.ex)
    error: def transact/2 defines defaults multiple times. Elixir allows defaults to be declared once per definition. Instead of:

        def foo(:first_clause, b \\ :default) do ... end
        def foo(:second_clause, b \\ :default) do ... end

    one should write:

        def foo(a, b \\ :default)
        def foo(:first_clause, b) do ... end
        def foo(:second_clause, b) do ... end

    │
 11 │   def transact(fun, opts \\ []) do
    │       ^
    │
    └─ lib/reprod.ex:11:7


== Compilation error in file lib/reprod.ex ==
** (CompileError) lib/reprod.ex: cannot compile file (errors have been logged)
    lib/reprod.ex:11: (module)

I made a project to reproduce the issue: https://github.com/kmc-firework/reprod

Expected behavior

should compile

[josevalim]

It doesn’t compile because Ecto.Repo defined its own def transact with default arguments, and now you are defining another one on top, leading to multiple defaults.

[josevalim]

I will try to include information about where the first default clause was defined.

[kmc-firework]

That make sense, having a namespace collision, I didn't realize the function wrapped an ecto function itself. Thank you!