This Issue is related to a few issues that have cropped up on the older version of this repository:

adikari/monorepo-diff-buildkite-plugin#68
adikari/monorepo-diff-buildkite-plugin#140

As well as the unmerged PRs:

adikari/monorepo-diff-buildkite-plugin#69
adikari/monorepo-diff-buildkite-plugin#144

The basic issue at hand is that the monorepo-diff-buildkite-plugin downloads a new copy of the binary every time it is run.

This is both a reliability issue (eventually, GitHub will 503 you for downloading the binary from releases so many times) as well as a security issue (if the binary was modified, there's no way to validate a checksum and ensure you always install the one you wanted).