Helm based repo with gitlab ci/cd

Hi, I have got a simple helm based repository with a single chart and a single deployment. I want to use gitlab ci/cd autodevops on my repo to create the deployment. I can’t get to do this at all. I have tried various options, like creating a .chart folder, updating AUTO_DEVOPS_CHART variable, etc. but to no avail.
I constantly get the following error:
Step 5/11 : RUN /bin/herokuish buildpack build

184 —> Running in 8161d67f8bfb

185 -----> Unable to select a buildpack

186 The command ‘/bin/sh -c /bin/herokuish buildpack build’ returned a non-zero code: 1