ci: force make vars for arm build

Jenkinsfile

@@ -118,17 +118,22 @@ spec:
             cd "${SRC_DIR}"
 
             export DOCKER_BUILDKIT=1
-            export VERSIONTAG="${VERSIONTAG}"
-            export BASEIMAGETAG="${VERSIONTAG}"
-            export IMAGENAMESPACE="${REGISTRY}"
-            export BASEIMAGENAMESPACE="${REGISTRY}"
-            export PULL_BASE_FROM_DOCKERHUB=false
-            export BUILD_BASE=true
-            export BUILDTRIVYADP=false
-            export BUILD_INSTALLER=true
 
+            # Harbor's root Makefile hard-sets many defaults (e.g. IMAGENAMESPACE=goharbor,
+            # PULL_BASE_FROM_DOCKERHUB=true). Environment exports are not sufficient because
+            # makefile assignments override the environment. Pass overrides on the make
+            # command line so they win.
             make compile
-            make build
+            make \
+              VERSIONTAG="${VERSIONTAG}" \
+              BASEIMAGETAG="${VERSIONTAG}" \
+              IMAGENAMESPACE="${REGISTRY}" \
+              BASEIMAGENAMESPACE="${REGISTRY}" \
+              PULL_BASE_FROM_DOCKERHUB=false \
+              BUILD_BASE=true \
+              BUILDTRIVYADP=false \
+              BUILD_INSTALLER=true \
+              build
 
             # Retag a few upstream image names to our internal naming convention
             # (so Helm values can keep using `harbor-*` consistently).