When running a snyk command, you may want to pass additional arguments to the package manager. Two hyphens (--) indicate to snyk that the arguments that follow are to be passed through to the underlying command that is sent to the package manager.
Usage:
snyk <COMMAND> [<OPTIONS>] -- [<ARGUMENTS>]
For example, you may want to tell a Maven project to use a specific settings.xml file:
snyk test -- "-s settings.xml"
The snyk commands supported for this functionality are snyk test and snyk monitor.