SkipLibCheck fails to work in multi-project set-up

**TypeScript Version:** 3.8. Beta <!-- Search terms you tried before logging this (so others can find this issue more easily) --> **Search Terms:** skiplibcheck **Steps to reproduce** 1. Extract the attached zip file to a folder and open `repro.sln` in Visual Studio (I'm using 2019) 2. Expand the `npm` folder on project B and install the missing `@azure/storage-blob` package. 3. Rebuild the solution. **Expected behavior:** No build errors. **Actual behavior:** 2 errors: > error TS2740: Build:Type 'Buffer' is missing the following properties... > error TS2345: Build:Argument of type 'ErrnoException' is not assignable... **Explanation** We want have a custom definition for NodeJS. The npm package imported in Project B also has its own (incomplete) definition. So, we've added `skiplibcheck` to all the projects. Project B builds fine by itself. Project C references some NodeJS types. Project C also builds fine by itself. Project A references types from both B and C. When attempting to build A, we get the error above. **But** the error is for project C. Basically, when building Project A, the `skiplibcheck` option is being ignored and the incomplete NodeJS definition from the imported package is being used. **Further Observations** Curiously, if file `A/foo/bar.ts` is moved to `A/bar.ts` (and the imports amended) the build compiles fine. **Attachment** [Repro.zip](https://github.com/microsoft/TypeScript/files/4128129/Repro.zip)