__ENV__.file

See https://hexdocs.pm/elixir/Kernel.SpecialForms.html#ENV/0

it isn’t for a stack trace. I have some resource e.g. an image in /lib/my_image.png and i have a module in lib/my_app.ex. And i want to work with that image in this module. I only know the relative path from the module to the image, it’s constant. But for this i need path to the current module. I can’t build path to the image from the root, because i don’t know where was my program run. it may run by mix then it will be the root of my app and if it’s an umbrella project it will be the project root. And also some one can run my module without mix.

Modules aren’t run, they are loaded.

If you process those files at compile time and do not use that path at runtime anymore, everything should be fine, but when you use the path during runtime and move the application to another computer or another path, without recompiling (eg. a distillery release) it will fail, because all pathes __ENV__.file is only valid during compilation.

If you want to integrate files into your release and load/process them at runtime use priv/-folder as briefly explained in another post:

What exactly are you searching for?

The path to the currently executed *.exs? The path to the current modules sourcefile? The path to the current modules BEAM-file?

This path is not absolute, and also it’s pointing to the source file. OP did not yet confirm if he searches for the source file or the actual BEAM.

Also using __ENV__ will print patches from the build system on the prod system, where the pointed to file might not exist at all.