I encountered an error similar to #105 and I believe that the error is related to the breaking changes made by Composer 2.

Specifically:

• vendor/composer/installed.json format changed:
  • packages are now wrapped into a "packages" top level key instead of the whole file being the package array
  • packages now contain an "installed-path" key which lists where they were installed
  • there is a top level "dev" key which stores whether dev requirements were installed or not