Listing installed plugins on Windows requires the extension to be set in
the ListOptions, otherwise they are not discovered.
While working on the discovery code, and consolidating it in a single
location, we've forgotten to pass the argument to ListInstallations, so
that makes it impossible to automatically discover installed components
on Windows.
This commit fixes this issue for the plugins required, and the general
discovery process during build/validate.
Since we'll only look in the plugin directory, and not from multiple
sources now, for installing/listing plugins, we can simplify the
structures which used to accept multiple directories so they only accept
one.
Since we're removing the alternative plugin installation directories in
favour of only supporting installing them in the PACKER_PLUGIN_PATH
directory, we only return one directory when getting the known plugin
directories.
The enumeration for FlagSetFlags, which presumably was added when the
Meta structure was introduced, aims to pre-populate the flagset for a
subcommand with a series of arguments.
However, despite it being documented, it is actually not used, and
therefore can safely be removed from the codebase.
* Updating the license from MPL to Business Source License
Going forward, this project will be licensed under the Business Source License v1.1. Please see our blog post for more details at https://hashi.co/bsl-blog, FAQ at https://hashi.co/license-faq, and details of the license at www.hashicorp.com/bsl.
* Update copyright file headers to BUSL-1.1
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Co-authored-by: hashicorp-copywrite[bot] <110428419+hashicorp-copywrite[bot]@users.noreply.github.com>