erroring if version is invalid

pipeline/git/git.go

@@ -1,11 +1,21 @@
 package git
 
 import (
+	"regexp"
 	"strings"
 
 	"github.com/goreleaser/goreleaser/context"
 )
 
+// ErrInvalidVersionFormat is return when the version isnt in a valid format
+type ErrInvalidVersionFormat struct {
+	version string
+}
+
+func (e ErrInvalidVersionFormat) Error() string {
+	return e.version + " is not in a valid version format"
+}
+
 // Pipe for brew deployment
 type Pipe struct{}
 
@@ -36,5 +46,8 @@ func (Pipe) Run(ctx *context.Context) (err error) {
 	}
 	// removes usual `v` prefix
 	ctx.Version = strings.TrimPrefix(tag, "v")
+	if matches, err := regexp.MatchString("[0-9.]+", ctx.Version); !matches || err != nil {
+		return ErrInvalidVersionFormat{ctx.Version}
+	}
 	return
 }