fix: debug skip

Signed-off-by: Carlos Alexandro Becker <caarlos0@gmail.com>

internal/middleware/skip/skip.go

@@ -2,6 +2,9 @@
 package skip
 
 import (
+	"fmt"
+
+	"github.com/apex/log"
 	"github.com/goreleaser/goreleaser/internal/middleware"
 	"github.com/goreleaser/goreleaser/pkg/context"
 )
@@ -10,6 +13,8 @@ import (
 type Skipper interface {
 	// Skip returns true if the Piper should be skipped.
 	Skip(ctx *context.Context) bool
+
+	fmt.Stringer
 }
 
 // Maybe returns an action that skips immediately if the given p is a Skipper
@@ -18,6 +23,7 @@ func Maybe(skipper interface{}, next middleware.Action) middleware.Action {
 	if skipper, ok := skipper.(Skipper); ok {
 		return func(ctx *context.Context) error {
 			if skipper.Skip(ctx) {
+				log.Debugf("skipped %s", skipper.String())
 				return nil
 			}
 			return next(ctx)