Pass KEEPBUNDLE in Docker build environment.
@@ -31,6 +31,7 @@ export DOCKERFILE
# `docs/sources/contributing/devenvironment.md ` and `project/PACKAGERS.md` have some limited documentation of some of these
DOCKER_ENVS := \
-e BUILDFLAGS \
+ -e KEEPBUNDLE \
-e DOCKER_BUILD_GOGC \
-e DOCKER_BUILD_PKGS \
-e DOCKER_CLIENTONLY \