Missing jar (from a Nexus 2 proxying a Nexus 3 which proxies RSO)

output.log

labyrinth:nexus-servlet danielsauble$ mvn clean install -DskipTests
[INFO] Scanning for projects...
[INFO] Inspecting build with total of 1 modules...
[INFO] Installing Nexus Staging features:
[INFO]   ... total of 1 executions of maven-deploy-plugin replaced with nexus-staging-maven-plugin
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building org.sonatype.nexus:nexus-servlet 3.1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[WARNING] The POM for bitwalker:UserAgentUtils:jar:1.12 is missing, no dependency information available
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.248 s
[INFO] Finished at: 2016-04-08T09:55:42-07:00
[INFO] Final Memory: 17M/331M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal on project nexus-servlet: Could not resolve dependencies for project org.sonatype.nexus:nexus-servlet:bundle:3.1.0-SNAPSHOT: Failure to find bitwalker:UserAgentUtils:jar:1.12 in http://localhost:8082/nexus/content/groups/dev2/ was cached in the local repository, resolution will not be reattempted until the update interval of nexus has elapsed or updates are forced -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/DependencyResolutionException