thank you for this nice tool which is very helpful in extracting the dependency licenses from a Dart project, and saved me a lot of work ๐
I have a small improvement idea: Sometimes dependencies do not have a license (e.g. the "builtin" flutter_localizations) which results in the license_gatherer to simply abort with an error, as implemented here:
"Could not find license file for '${package.name}' in '${package.path}'",
In my opinion, it would be sufficient to report the fact that a dependency does not have a license to stderr or so, and continue writing the NOTICE file.