Elixir recompiling all files each time

Questions & Help Questions
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1

I’m working on a fairly large app and when running the tests it recompiles all files each time. This is pretty annoying, obviously, as it takes quite some time.

I have tracked it down and the issue seems that the “compile manifest” that is written after compilation (in the Mix.Compilers.Elixir module) cannot be read back in (throwing a badarg on this line ), so mix considers all files “new” and compiles everything.

When I remove the compressed: 9 option to :term_to_binary, all goes well. @michalmuskala suggested I post this here because more people might have the same issue. It could have something to do with a bug in Erlang’s zlib. I am already on the latest Erlang (19.2), running on Arch Linux.

Using different Erlang versions does not seem to differ; I have built several Erlang versions using kerl and keep getting the same error.

2

I think it might help us if you were able to include your manifest file here or gist it. Could you please do that?

3

Sure, I’ll see if I can produce a manifest that exhibits the same behaviour that doesn’t contain trade secrets :wink:

Edit: no longer needed, as its a known Erlang bug

4

@arjan you are hitting the issue that :erlang.binary_to_term has a bug when uncompressing some data depending on the zlib version. Here is the discussion about it in the Erlang mailing list: [erlang-questions] Problem with binary_to_term on different machines

You can either change zlib OR check if latest Erlang has solved it.

5

Thanks for the link, latest Erlang does not fix it, I’ll try applying the patch he mentions.

Would you consider it a bug that mix swallows the error? (as seen here)? Took me quite a while to figure out :slight_smile:

6

What a concidence, yesterday they released 19.3, which contains a fix for this. (issue OTP-14159). Case closed!