Specifies a sorted list of product flavors that the plugin should try to use when a direct
variant match with a local module dependency is not possible.
Android plugin 3.0.0 and higher try to match each variant of your module with the same one
from its dependencies. For example, when you build a "freeDebug" version of your app, the
plugin tries to match it with "freeDebug" versions of the local library modules the app
However, there may be situations in which, for a given flavor dimension that exists in
both the app and its library dependencies, your app includes flavors that a dependencydoes not. For example, consider if both your app and its library dependencies include a
"tier" flavor dimension. However, the "tier" dimension in the app includes "free" and "paid"
flavors, but one of its dependencies includes only "demo" and "paid" flavors for the same
dimension. When the plugin tries to build the "free" version of your app, it won't know which
version of the dependency to use, and you'll see an error message similar to the following:
Error:Failed to resolve: Could not resolve project :mylibrary.
In this situation, you should use
matchingFallbacks to specify alternative
matches for the app's "free" product flavor, as shown below:
// In the app's build.gradle file.
// Because the dependency already includes a "paid" flavor in its
// "tier" dimension, you don't need to provide a list of fallbacks
// for the "paid" flavor.
// Specifies a sorted list of fallback flavors that the plugin
// should try to use when a dependency's matching dimension does
// not include a "free" flavor. You may specify as many
// fallbacks as you like, and the plugin selects the first flavor
// that's available in the dependency's "tier" dimension.
matchingFallbacks = ['demo', 'trial']
Note that, for a given flavor dimension that exists in both the app and its library
dependencies, there is no issue when a library includes a product flavor that your app does
not. That's because the plugin simply never requests that flavor from the dependency.
If instead you are trying to resolve an issue in which a library dependency includes aflavor dimension that your app does not, use missingDimensionStrategy.