Ambient declarations (.d.ts) not being discovered anymore

[atrauzzi]

Suddenly this morning, a particular ambient declaration has started causing errors, preventing anything from working.

This is the project & branch I'm working in: https://github.com/atrauzzi/gerty/tree/hashi-gerty

I think it's a fairly straightforward webpack & ts-node setup. Again, it's been working up until this morning...

$ cross-env NODE_ENV=development node_modules/webpack-dev-server/bin/webpack-dev-server.js --port 5174 --inline --disable-host-check --config=webpack.debug.ts

/Users/atrauzzi/Development/atrauzzi/gerty/node_modules/ts-node/src/index.ts:261
    return new TSError(diagnosticText, diagnosticCodes)
           ^
TSError: ⨯ Unable to compile TypeScript:
src/Util.ts(2,24): error TS7016: Could not find a declaration file for module 'sudo-prompt'. '/Users/atrauzzi/Development/atrauzzi/gerty/node_modules/sudo-prompt/index.js' implicitly has an 'any' type.
  Try `npm install @types/sudo-prompt` if it exists or add a new declaration (.d.ts) file containing `declare module 'sudo-prompt';`

    at createTSError (/Users/atrauzzi/Development/atrauzzi/gerty/node_modules/ts-node/src/index.ts:261:12)
    at getOutput (/Users/atrauzzi/Development/atrauzzi/gerty/node_modules/ts-node/src/index.ts:367:40)
    at Object.compile (/Users/atrauzzi/Development/atrauzzi/gerty/node_modules/ts-node/src/index.ts:558:11)
    at Module.m._compile (/Users/atrauzzi/Development/atrauzzi/gerty/node_modules/ts-node/src/index.ts:439:43)
    at Module._extensions..js (internal/modules/cjs/loader.js:718:10)
    at Object.require.extensions.(anonymous function) [as .ts] (/Users/atrauzzi/Development/atrauzzi/gerty/node_modules/ts-node/src/index.ts:442:12)
    at Module.load (internal/modules/cjs/loader.js:605:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:544:12)
    at Function.Module._load (internal/modules/cjs/loader.js:536:3)
    at Module.require (internal/modules/cjs/loader.js:643:17)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

I know that's a common error message, but I had already done what's necessary to mitigate it. Here is my ambient.d.ts at the root of the project:

declare module "*.jpg" {
    const path: string;
    export default path;
}

declare module "hostile" {
    const hostile: any;
    export default hostile;
}

declare module "sudo-prompt" {

	export function exec(cmd: string, options: { name?: string, icns?: string }, callback: (error: string, stdout: string, stderr: string) => void): any;
}

declare module "webpack-shell-plugin";

declare module "ps-tree";

[atrauzzi]

Hmm... I think I managed to get some vague insight into what's going on here. Seems like crossing the boundary of another project might be upsetting things a little.