So if I add break points in .dart files that are located in /web directory of my project, it works fine. For example I'm using AngularDart and the main.dart file works. However when I try to put a breakpoint in anything in the /lib directory, Dartium doesn't stop on them.
How can I get the breakpoints in Dartium to work with the /lib directory?
Note that I've tried putting breakpoints with Dart Editor, IntelliJ with Dart Plugin and also directly in Dartium and nothing works. Is this intended?
To set breakpoints in dependencies search the source inside the (no domain) node and set the breakpoint there. Breakpoints don't hit when set somewhere in the packages node.
You can also use the breakpoint statement for the debugger top pop up. See Does Dart have a 'breakpoint' statement? for more details.
I will combine the accepted answer + comment to that answer. Breakpoints 100% works only when you set them for files inside (no domain) category on Sources tab.
As I understand, in category with your domain name they are working only for files that was included with <script> tag. They won't work for imported files.
I have created an issue: Dartium ignores breakpoints set not in (no domain) category.
If you set break pointors from Dart Editor, then you should run your application from Dart Editor.
If you're using Dartium only, then you should set break pointors from Chrome Developer Tool. (Accepted answer)
来源：https://stackoverflow.com/questions/26822902/breakpoints-in-dartium-not-working