get_snapshot: Use UPSTREAM_GIT_BRANCH instead of HEAD

get_snapshot

@@ -54,7 +54,7 @@ else
     exit 1
 fi
 
-git_version=$(git describe --tags HEAD)
+git_version=$(git describe --tags "${UPSTREAM_GIT_BRANCH}")
 if [[ "$git_version" = *2.6.3* ]]; then
   package_version=$(echo "$git_version" | sed -e 's/^v//' -e 's/-/+t/' -e 's/-/./g')
 else
@@ -75,4 +75,4 @@ gzip -vf9 "${tarball}"
 sha256sum "${tarball}.gz"
 
 # store package version for build scripts
-echo -e "${package_version}\t$(git rev-parse HEAD)\t$(basename "${tarball}.gz")\t${UPSTREAM_GIT_BRANCH}" > "${workdir}/${PROJECT}.version"
+echo -e "${package_version}\t$(git rev-parse "${UPSTREAM_GIT_BRANCH}")\t$(basename "${tarball}.gz")\t${UPSTREAM_GIT_BRANCH}" > "${workdir}/${PROJECT}.version"