How to measure test coverage difference in Go

Question

Is there a way to get the difference in coverage percentage? My goal is to fail a build when the coverage has decreased.

I can easily get the current coverage percentage and compare it to a threshold number. However I want to compare it to the original coverage percentage.

Currently getting coverage report with gotestsum --junitfile-testcase-classname=short --junitfile-testsuite-name=relative -coverprofile="service.out" ./...