add BUILDKITE_GIT_FETCH_FLAGS

Author: pzeballos

hooks/checkout

@@ -42,11 +42,13 @@ if [[ ! -d .git ]]; then
 fi
 
 git clean -ffxdq
-# fetch branch if commit is HEAD
+
+# fetch branch if commit is HEAD, respecting BUILDKITE_GIT_FETCH_FLAGS if set
+FETCH_FLAGS="${BUILDKITE_GIT_FETCH_FLAGS:-}"
 if [[ ${BUILDKITE_COMMIT} = "HEAD" ]]; then
-    git fetch --depth 1 origin "${BUILDKITE_BRANCH}"
+    git fetch --depth 1 ${FETCH_FLAGS} origin "${BUILDKITE_BRANCH}"
 else
-    git fetch --depth 1 origin "${BUILDKITE_COMMIT}"
+    git fetch --depth 1 ${FETCH_FLAGS} origin "${BUILDKITE_COMMIT}"
 fi
 
 git sparse-checkout set ${NO_CONE_PARAM:+--no-cone} "${CHECKOUT_PATHS[@]}"