I am trying to install a library from the source that makes use of Poetry, but I get this error error: Multiple top-level packages discovered in a flat-layout: ['tulips', 'fixtures']. To avoid accidental inclusion of unwanted files or directories, setuptools will not proceed with this build. If you are trying to create a single distribution with multiple packages on purpose, you should not rely on automatic discovery. Instead, consider the following options: 1. set up custom discovery (`find` directive with `include` or `exclude`) 2. use a `src-layout` 3. explicitly set `py_modules` or `packages` with a list of names To find more information, look for "package discovery" on setuptools docs What do I need to do to fix it? Continue reading...