Why aren't modules prefixed their package name?

Haskell currently allows you to use package-qualified imports by using the PackageImports extension. The documentation for this extension notes that “You probably don’t need to use this feature” and that “It can lead to fragile dependencies in the common case: modules occasionally move from one package to another, rendering any package-qualified imports broken”

ghc.gitlab.haskell.org

6.3.2. Package-qualified imports — Glasgow Haskell Compiler 9.15.20260306...