Using older version of PGI compiler 17.10 does not work about hpc-container-maker

[samcmill]

PGI only makes the most recent version of the PGI Community Edition available for download. Currently that is version 18.4.

The version parameter does not actually control the version that is downloaded. However, the version is needed to properly configure the component, e.g., $PATH. Hence this comment.

The documentation in RECIPES.md is

- `version`: The version of the PGI compiler to use.  Note this value
  is currently only used when setting the environment and does not
  control the version of the compiler downloaded.  The default value
  is `18.4`.

If you have a tarball of a previous version of the PGI compiler, you can use it with the PGI building block via the tarball parameter:

Stage0 += pgi(tarball='pgilinux-2017-1710-x86_64.tar.gz', ...)

But if you do not have a local copy of a previous version, there is no combination of options that will download an older version.

If you have a PGI Professional Edition license, you can download older versions manually from the website and use the tarball option.