There seems to be a problem with the Typescript compiler constantly altering the structure of the output directory, causing issues with linked dependents.
Previously, it looked like this:
+- dist
+- index.d.ts
+- index.js
Now, unexpectedly it looks like this:
+- dist
+- src
+- index.d.ts
+- index.js
(I already know the solution, but leaving a reminder for my future self because I've dealt with this issue twice before!)