fix hook scripts

hooks/post_checkout

@@ -1,18 +1,14 @@
 #!/usr/bin/env bash
-env
-set -x
 
-BUILD_ARCH=$(echo "${DOCKERFILE_PATH}" | cut -d'.' -f2)
-
-[ "${BUILD_ARCH}" == "Dockerfile" ] && \
+[[ "${DOCKER_TAG}" == "latest" ]] && \
  { echo 'qemu-user-static: Download not required for this arch'; exit 0; }
 
 TAGS_API="https://api.github.com/repos/multiarch/qemu-user-static/tags"
 URL="https://github.com/multiarch/qemu-user-static/releases/download"
 LATEST_TAG=$(curl -Ls $TAGS_API | \
  awk -F'"' '/name.*v[0-9]/ {print $4; exit}')
-STATIC_ARCH=$([ "${BUILD_ARCH}" == "armhf" ] && \
- echo "${BUILD_ARCH::-2}" || echo "${BUILD_ARCH}")
+ARCH=$([[ "${DOCKER_TAG}" == "armhf" ]] && \
+ echo "${DOCKER_TAG::-2}" || echo "${DOCKER_TAG}")
 
-curl -Ls "${URL}/${LATEST_TAG}/x86_64_qemu-${STATIC_ARCH}-static.tar.gz" | \
+curl -Ls "${URL}/${LATEST_TAG}/x86_64_qemu-${ARCH}-static.tar.gz" | \
  tar xzv

hooks/pre_build

@@ -1,8 +1,6 @@
 #!/usr/bin/env bash
 
-BUILD_ARCH=$(echo "${DOCKERFILE_PATH}" | cut -d'.' -f2)
-
-[ "${BUILD_ARCH}" == "Dockerfile" ] && \
+[[ "${DOCKER_TAG}" == "latest" ]] && \
  { echo 'qemu-user-static: Registration not required for this arch';exit 0; }
 
 docker run --rm --privileged multiarch/qemu-user-static:register --reset