Error: Internal error: Defined value expected, but got undefined.

[noppej]

The quicktype CLI fails with the above error, when executing the following
quicktype --lang rs --derive-debug --density dense --visibility private --out debugProtocolTypes.rs --src-lang typescript --src-urls https://raw.githubusercontent.com/microsoft/vscode/master/src/vs/workbench/contrib/debug/common/debugProtocol.d.ts

The same input file and options on quicktype.io produces code successfully.