Besides the excellent replies above, there are likely places we can optimize Mix or the compiler. It should not take 1 minute to compile 100 files, so I am assuming the slowdown is elsewhere and not in the compiler per-se. Can you please try doing the same IO.inspect change as before and then running:
MIX_DEBUG=1 mix compile --profile=time
and putting the output in a gist? I am particularly interested in the different between these times:
[profile] Finished compilation cycle of 2 modules in 5ms
[profile] Finished group pass check of 2 modules in 0ms
<- Ran mix compile.elixir in 21ms
My theory is that there is a large overhead on mix compile.elixir compared to the actual compiler. Looking at the code, I can think of some ideas for improvements, so I will try them out now.
Btw, if you are interested, please ask your employer if they would be willing to share it with me. If necessary, we could sign a terms of service through Dashbit so we are covered by confidentiality agreements.
