golang-github-gofrs-flock-dev 0.7.1-2 (armhf binary) in ubuntu focal

 flock implements a thread-safe sync.Locker interface for file locking.
 It also includes a non-blocking TryLock() function to allow locking
 without blocking execution.
 .
 This library is formerly known as "github.com/theckman/go-flock".