问题
What is the difference in dependencies and dev_dependencies in a pubspec.yaml? It seems that when I run pub get the dev_dependencies aren't downloaded.
回答1:
dev_dependencies are only used when you run pub get/pub upgrade for the package directly where they are in the pubspec.yaml. dev_dependencies of dependent packages (dependencies or dev_dependencies) are always ignored. Hence dev_dependencies are only relevant to tasks relevant to development (test, tool, example,... ) of your package but not when it's used as a dependency.
See also https://www.dartlang.org/tools/pub/pubspec.html
回答2:
If your package (say A) depends on another package (say B) (which further has dev-dependencies), then your package (A) simply ignores the dev-dependencies used by that package (B).
However, your package (A) will depend on the packages (which are specified under dependency) of B package.
来源：https://stackoverflow.com/questions/32108457/whats-the-difference-between-pub-dependencies-and-dev-dependencies