In golang/dep, we are using semver.NewConstraintIC to parse raw strings as constraints and some of them aren't being handled as expected:

• v1.12.0-g2fd980e properly returns (semver.rangeConstraint) ^1.12.0-g2fd980e
• v0.12.0-12-g2fd980e returns (semver.rangeConstraint) >=0.12.0, <=12.0.0-g2fd980e, when I expected ^1.12.0-g2fd980e
• v1.12.0-2-g2fd980e returns (semver.rangeConstraint) >=1.12.0, <=2.0.0-g2fd980e, when I expected ^v1.12.0-2-g2fd980e.
• v1.3.1-1-gf12c623 returns an unexpected (semver.none) . I expected ^1.3.1-1-gf12c623, or at the very least an error.

Essentially the dash in the prerelease tag is causing the function parse the input a range between v1.3.1 to 1-gf12c623.

I'm going to try having it first check if the input string is a valid version first, and if that pans out, submit a PR.