Shared validation of OptionParser leftovers for spec mix tasks.
validate/3 returns a uniform error message naming the task, while
validate!/3 keeps the raising API for callers that do not need to emit
output before rejection.
Shared validation of OptionParser leftovers for spec mix tasks.
validate/3 returns a uniform error message naming the task, while
validate!/3 keeps the raising API for callers that do not need to emit
output before rejection.