Building Error: error TS2420: Class 'RenderedCommon' incorrectly implements interface 'IRenderer'.

[EternalConfession]

I met the following error when run
yarn run build

node_modules/@jupyterlab/rendermime/lib/widgets.d.ts(7,31): error TS2420: Class 'RenderedCommon' incorrectly implements interface 'IRenderer'.
Types of property 'title' are incompatible.
Type 'Title' is not assignable to type 'Title'. Two different types with this name exist, but they are unrelated.
Types of property 'owner' are incompatible.
Type 'Widget' is not assignable to type 'Widget'. Two different types with this name exist, but they are unrelated.
Types of property 'layout' are incompatible.
Type 'Layout' is not assignable to type 'Layout'. Two different types with this name exist, but they are unrelated.
Property 'init' is protected but type 'Layout' is not a class derived from 'Layout'.
error Command failed with exit code 1.

[gjamesli2126]

Same issue.
Has it been solved?

[EternalConfession]

Not yet and I gave up.
It seems that this porject is no longer being maintained.

[mhrvol]

I came across similar issue, what might help is adding "skipLibCheck": true to the tsconfig.json's compilerOptions.

The issue is that @Lumino staff needs to be locked down for certain checks (instanceof + typing). Extension developers has little to none control over which version it will actually run with, as the application itself will allow only the versions it was shipped with.

Note that this might not be ideal solution if you use more libraries, not just lumino widgets.

[xiaohk]

Same issue here