If the git tag is a valid semantic version string, the system provides the tag as a semver string.
DRONE_SEMVER=1.2.3-alpha.1
The semver string is also available in the following formats:
DRONE_SEMVER_SHORT=1.2.3
DRONE_SEMVER_PATCH=3
DRONE_SEMVER_MINOR=2
DRONE_SEMVER_MAJOR=1
DRONE_SEMVER_PRERELEASE=alpha.1