whalespotter is
The simplest solution is to execute
cargo install whalespotter
If you want to play with the code, you'll probably fetch the repository. From there you can do
cargo build --release
and the executable will be in target/release.
Note that the current version of whalespotter doesn't run on windows (due to some additional code to deduplicate inodes).
Pass the desired path:
whalespotter ~
xdg-open)