Building without an mbed account

Following the instructions at https://lancaster-university.github.io/microbit-docs/offline-toolchains/, when running `yotta build`, I get:

```
info: get versions for bbc-microbit-classic-gcc
info: download bbc-microbit-classic-gcc@0.2.0 from the public module registry

You need to log in to do this.
Press enter to continue.
Your browser will open to complete login.

waiting for response...
If you are unable to use a browser on this machine, please copy and paste this URL into a browser:
https://yotta.mbed.com/#login/(…)
```

I am quite surprised that for something that seems open-source (http://yotta.mbed.com/#/target/bbc-microbit-classic-gcc/0.2.0 says "Licenses: Apache-2.0"), an account is required just to download public code (as opposed to publishing anything).

I would much rather not give identifying information to a private company just to try out a "hello world" program.

Is there a way to obtain a yotta target without an mbed account?