Ability to have secondary providers

[Piedone]

Is your feature request related to a problem? Please describe.

Using LibMan puts the chosen provider as a critical dependency of your build. This is expected, but also risky, especially since we're talking about unofficial ones (although we could also have NPM as a provider: #807). If the provider fails, all your builds will fail.

Describe the solution you'd like

Be able to configure multiple providers, or to not break the current configuration format, multiple secondary providers. These would be used as a fallback if requests to the primary provider fail.

Describe alternatives you've considered

Having NPM as a provider: #807.

Additional context

Nothing else.

[jimmylewis]

This is a valid concern, but is largely mitigated by:

• the providers we have today are designed to offer high availability as well, even including (their own suggestions) to be used in <script src="..."> tags for direct consumption.
• because build tools are expected to run many times, libman does cache the library contents upon the first download.
  • for CI scenarios, many CI platforms also offer a way to support a cache for dependencies, to avoid repeatedly downloading assets on each build.

Having fallback providers is a very difficult challenge, as described in #692 (comment)

[Piedone]

Thank you for your quick reply again.

Yeah, good points. I'll reply under the other issue.