Linting in grafana/jsonnet-libs was broken for a long time due to a bug in evaluating exit codes when doing the lint. TL;DR, make lint fails with a non-zero error code only if the last checked jsonnet file check failed. Similar issue seems to have been already fixed in deployment_tools repo.

Moreover, the linting docker image uses an image from kausal, despite of jsonnet-libs/build/Makefile referring to a grafana-hosted image.