diff --git a/Makefile b/Makefile
index ad0217b969d..04254f00583 100644
--- a/Makefile
+++ b/Makefile
@@ -13,6 +13,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+ifeq (,$(shell echo $$DEBUG))
+else
+SHELL = bash -x
+endif
+
 # Get the currently used golang install path (in GOPATH/bin, unless GOBIN is set)
 ifeq (,$(shell go env GOBIN))
 GOBIN=$(shell go env GOPATH)/bin
@@ -27,7 +32,7 @@ GIT_TAG ?= dirty-tag
 GIT_VERSION ?= $(shell git describe --tags --always --dirty)
 GIT_HASH ?= $(shell git rev-parse HEAD)
 DATE_FMT = +%Y-%m-%dT%H:%M:%SZ
-SOURCE_DATE_EPOCH ?= $(shell git log -1 --pretty=%ct)
+SOURCE_DATE_EPOCH ?= $(shell git log -1 --no-show-signature --pretty=%ct)
 ifdef SOURCE_DATE_EPOCH
     BUILD_DATE ?= $(shell date -u -d "@$(SOURCE_DATE_EPOCH)" "$(DATE_FMT)" 2>/dev/null || date -u -r "$(SOURCE_DATE_EPOCH)" "$(DATE_FMT)" 2>/dev/null || date -u "$(DATE_FMT)")
 else