Prerelease gems can be specified in maven dependencies using mavengem, but it appears that transitive prerelease dependencies try to resolve with a -SNAPSHOT suffix.

From JRuby while working on jruby/jruby#8221

[ERROR] Failed to execute goal on project jruby-stdlib: Could not resolve dependencies for project org.jruby:jruby-stdlib:jar:9.4.8.0-SNAPSHOT: Failed to collect dependencies at rubygems:subspawn:gem:0.2.0.pre1 -> rubygems:subspawn-common:gem:[0.2.0.pre1-SNAPSHOT,0.2.99999]: No versions available for rubygems:subspawn-common:gem:[0.2.0.pre1-SNAPSHOT,0.2.99999] within specified range -> [Help 1]

In this example, the subspawn 0.2.0.pre1 gem depends on subspawn-common 0.2.0.pre1, but mavengem tries to resolve the latter with a -SNAPSHOT suffix that does not exist.