Package 'log4dart' is depended on from both sources 'hosted' and 'git'
John is correct, the workaround is to specify the same git repo for log4dart that crimson does.
Packages are identified by their (source, description) pair. For hosted packages, the description is just the package name, but for Git packages the description also includes the Git URL. So two Git checkouts of log4dart from different repositories would also be incompatible.
I've opened two bugs to fix up the packages you're trying to use:
- https://github.com/Solvr/log4dart/issues/5 -- Update: fixed!
- https://github.com/chrisbu/CrimsonHttp/issues/7 -- Update: fixed!
I'm not sure why this would be an error for pub, but it appears that crimsonhttp is referencing the git version of log4dart. This is likely the cause of the error message.
To fix the issue, you could reference the git: version of log4dart in your own pubspec.