We recently released Nerves 1.4.0 and an update to the Nerves new project generator,
nerves_bootstrap. The biggest change is support for Elixir 1.8’s Mix target feature. This feature not only cleans up a Nerves project’s
mix.exs file, it also makes switching between compiling for your device and testing on your laptop easier. Dependencies are versioned together now rather than in multiple files where library versions could diverge between targets and your host.
If you have an existing Nerves project, you can upgrade to Nerves 1.4.0 without making any changes to your
mix.exs. It will still work, but without the new mix target support. When you’re ready, update instructions are at https://hexdocs.pm/nerves/updating-projects.html#updating-from-v1-3-x-to-v1-4-x.
After you update, be aware that the build output directory has changed. You may need to update any scripts that publish the firmware bundle file (.fw file). For example, the
upload script needed to change due to this. Be sure to update that library when you update.