This gist documents the steps to analyze the binary size allocation for SwiftLint (and other SwiftPM-based executables).
First, install Bloaty McBloatface: https://github.com/google/bloaty
Then run the following:
$ swift build -c release
$ ditto .build/release/swiftlint swiftlint-stripped
$ strip -rSTX swiftlint-stripped