Unnecessary dev dependencyDRT-W1678

The analyzer produces this diagnostic when there's an entry under dev_dependencies for a package that is also listed under dependencies. The packages under dependencies are available to all of the code in the package, so there's no need to also list them under dev_dependencies.

Example

The following code produces this diagnostic because the package meta is listed under both dependencies and dev_dependencies:

name: example
dependencies:
  meta: ^1.0.2
dev_dependencies:
  meta: ^1.0.2

Common fixes

Remove the entry under dev_dependencies (and the dev_dependencies key if that's the only package listed there):

name: example
dependencies:
  meta: ^1.0.2