I was updating my Rustler from 0.25 to 0.27, and when I ran mix deps.get, I got the following message which i’ve not seen before. Usually when there’s a dependency mismatch, it’ll state which packages are clashing and over what version they disagree. But this doesn’t have any of that info. I tried removing my mix.lock, and runnning mix deps.clean. If I remove rustler entirely from my mix.exs then it’ll run, and if my rustler is 0.25 it’ll run, but when I set it to 0.27 it fails.

Mix.ex

...
{:rustler, "~> 0.27.0"},
...

$ mix deps.get
Resolving Hex dependencies...
Resolution completed in 0.03s
Because your app depends on rustler empty which doesn't match any versions, version solving failed.
** (Mix) Hex dependency resolution failed

I can’t add the bold and code formatting, but the error message appears like this: “Because your app depends on rustler empty which doesn’t match any versions, version solving failed.”

EDIT:

It also happens if I try to change {:httpoison, "~> 1.0"}, to {:httpoison, "~> 2.0"},

Because your app depends on httpoison empty which doesn’t match any versions, version solving failed.

Also, your app here is verbatim, not something i’ve replaced to generalize it.