I installed Ubuntu on Windows for Elixir development as some of the packages I need are not Windows compatible. So I need to test/run my existing Phoenix/Elixir project from inside this Ubuntu command line.

I got Elixir/Erlang/Phoenix installed okay, but when I navigate to an existing directory where I have a project like cd /mnt/h/users/mike/documents/testserver/ and run iex -S mix phx.server I get:

==> file_system
Compiling 7 files (.ex)
** (EXIT from #PID<0.99.0>) an exception was raised:
    ** (File.Error) could not touch "/mnt/h/users/mike/documents/testserver/_build/dev/lib/file_system/ebin/Elixir.FileSystem.beam": not owner
        (elixir 1.16.0) lib/file.ex:631: File.touch!/2
        (elixir 1.16.0) lib/kernel/parallel_compiler.ex:334: anonymous fn/3 in Kernel.ParallelCompiler.write_module_binaries/3
        (elixir 1.16.0) lib/enum.ex:1264: anonymous fn/3 in Enum.flat_map/2
        (stdlib 5.2) maps.erl:416: :maps.fold_1/4
        (elixir 1.16.0) lib/enum.ex:2540: Enum.flat_map/2
        (elixir 1.16.0) lib/kernel/parallel_compiler.ex:260: Kernel.ParallelCompiler.spawn_workers/3
        (mix 1.16.0) lib/mix/compilers/elixir.ex:1002: anonymous fn/9 in Mix.Compilers.Elixir.compiler_loop/6

Do you know what this might represent?

I tried deleting the _build folder and letting it make it again but it just creates a new _build folder with only Elixir.FileSystem.beam and fails after that same error.

Is there some trick to running this setup I’m missing in terms of file access on Ubuntu on Windows?

If I try to access the project like nano mix.exs I can edit the file and save so I do have permissions but the Elixir build is not running.

elixir -v gives Erlang/OTP 26 & Elixir 1.16.0 which seems to be as expected.

Thanks for any help.