Maven Native Image plugin should fail if it cannot download reachability metadata

[odrotbohm]

If, for whatever reason, the reachability metadata cannot be downloaded, the console output looks as follows:

[INFO] --- native-maven-plugin:0.9.14:compile-no-fork (native-compile) @ restbucks ---
[ERROR] Failed to download from https://github.com/oracle/graalvm-reachability-metadata/releases/download/0.2.2/graalvm-reachability-metadata-0.2.2.zip: github.com
[WARNING] GraalVM reachability metadata repository is enabled, but no repository has been configured
…

still, the build still continues and, if it succeeds, is likely to produce an invalid binary. Does it make sense to abort the build if it is configured to use the metadata repository, but cannot download it? Additionally, does it make sense to cache the information downloaded so that it doesn't have to be redownloaded on every build (and by that make native builds implicitly require internet access?)