I'm not sure why but it looks like for builds with
the default locale is set to POSIX
Maybe it is me, but
LANG=C.UTF-8 seems like a more reasonable default.
I also have issues with locale in regards to Elixir:
warning: the VM is running with native name encoding of latin1 which may cause Elixir to malfunction as it expects utf8. Please ensure your locale is set to UTF-8
I figured out you can use this in your build manifest file to fix this issue:
environment: LANG: C.UTF-8