@jaredly there seems to be some permissions issue:

tar: could not chdir to '/Users/runner/runners/2.160.1/work/1/cache'

Information, ApplicationInsightsTelemetrySender correlated 1 events with X-TFS-Session f834923b-097f-4c7d-a958-c0c6379a4371
##[error]Process returned non-zero exit code: 1

I'm not sure what could be causing this, this command is part of the internal Cache saving scripts.

I thought it could be that I'm a contributor and there is some security issues, but in hello-reason I activated Azure cache in a PR like here and everything seemed to work: esy-ocaml/hello-reason#53.

@jordwalke @ulrikstrid have you run into this issue before?