@firesidewing

I was curious so I tried it out and it’s indeed slow:

iex(1)> :timer.tc fn -> Mix.install([:tails], force: true) end
{9605421, :ok} # nine seconds

Skimming the files, it seems to do attribute and function generation from external (?) resources in tails/lib/custom.ex at main · zachdaniel/tails · GitHub, so I guess that’s what is causing the long compilation time.

With profiler on:

[profile]     15ms compiling +      0ms waiting while compiling lib/color_classes.ex
[profile]     21ms compiling +      0ms waiting while compiling lib/doc.ex
[profile]     26ms compiling +      0ms waiting for module Tails.ColorClasses while compiling lib/colors.ex
[profile]    151ms compiling +      0ms waiting while compiling lib/custom.ex
[profile]   7878ms compiling +    143ms waiting for module Tails.Custom while compiling lib/tails.ex
[profile] Finished compilation cycle of 8 modules in 8024ms
[profile] Finished group pass check of 8 modules in 41ms

And by “attribute and function generation” I mean something like this

# try running it in IEx
defmodule SlowModule do
  for i <- 1..100_000 do
    def to_string(unquote(i)), do: unquote(to_string(i))
  end
end

Tails doesn’t do that exact thing, but I think it’s something similar. One possible fix is to do less of that, maybe splitting this work across modules, or using “smaller” data structures. And I think Tz had a similar problem in the past, and now it doesn’t. So it might be useful