In projects/mnemonic, the project link points at https://github.com/codesections/gutenberg-theme-demo, and the Cargo link seems to point to a completely different package ("This is a Rust port of the mnemonic encoder originally written in C by Oren Tirosh and available from: https://github.com/singpolyma/mnemonicode").
The former (link pointing at gutenberg-theme-demo) also seems to be a problem in a few other projects (Muon, zola themes).