General troubleshooting

`cargo-embed` problems

Most cargo-embed problems are either related to not having installed the udev rules properly (on Linux) or having selected the wrong chip configuration in Embed.toml so make sure you got both of those right.

If the above does not work out for you, you can open an issue in the discovery issue tracker. Alternatively you can also visit the Rust Embedded matrix channel or the probe-rs matrix channel and ask for help there.

Cargo problems

"can't find crate for `core`"

Symptoms

   Compiling volatile-register v0.1.2
   Compiling rlibc v1.0.0
   Compiling r0 v0.1.0
error[E0463]: can't find crate for `core`

error: aborting due to previous error

error[E0463]: can't find crate for `core`

error: aborting due to previous error

error[E0463]: can't find crate for `core`

error: aborting due to previous error

Build failed, waiting for other jobs to finish...
Build failed, waiting for other jobs to finish...
error: Could not compile `r0`.

To learn more, run the command again with --verbose.

Cause

You forgot to install the proper target for your microcontroller (thumbv7em-none-eabihf for v2 and thumbv6m-none-eabi for v1).

Fix

Install the proper target.

# micro:bit v2
$ rustup target add thumbv7em-none-eabihf

# micro:bit v1
$ rustup target add thumbv6m-none-eabi

Discovery