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* This is needed when the installation directory is also not on a
  file system shared throughout the cluster.

* When using the daint debug partition, the very tight limit on the
  number of jobs that can be submitted simultaneously might cause
  build errors.  The wrapper for salloc simply retries a bit later in
  this case.

* This is meant to facilitate debug builds or experiments with more
  aggressive optimizations.

* Also exploit /dev/shm for executable staging where possible.

* declare does not entirely behave like local.

* See announcement at
  https://user.cscs.ch/updates/#february-2022

* This should make it easier to establish what is being used when looking
  at config.log.