* Add ccache detection and use
* Install ccache on Linux and OS X Azure Pipelines workers.
* Enable ccache in GitHub Actions and Azure
* Temporarily error on error, not warning, when checking R package
* Several small simplifications based on draft pr review
* Update .ci/linux-steps.yaml
Co-authored-by: Ryan Curtin <ryan@ratml.org>
* Call `make` without `VERBOSE=1`
* Update .ci/macos-steps.yaml
Co-authored-by: Ryan Curtin <ryan@ratml.org>
* Update .ci/linux-steps.yaml
Co-authored-by: Ryan Curtin <ryan@ratml.org>
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Co-authored-by: Ryan Curtin <ryan@ratml.org>
