I've run into this in geronimo trunk.
Initial project state:
root pom includes dependency A in dependencyManagement.
this dependency is used (in dependencies) in several places including plugins/clustering/plugin-farm-datasource/
Snapshots for this project are deployed (at apache snapshot repo)
move A to dependencyManagement of plugins/system-database/pom.xml (also a pom packaging)
include in plugins/clustering/plugin-farm-datasource/pom.xml
(this is a car packaging project, using the geronimo car-maven-plugin)
now, clean the local repo and try to build the project from root.
pb:trunk david$ mvn clean install -Pit
[INFO] Scanning for projects...
[INFO] snapshot org.apache.geronimo.plugins:system-database:2.2-SNAPSHOT: checking for updates from apache.snapshots
[INFO] snapshot org.apache.geronimo.plugins:system-database:2.2-SNAPSHOT: checking for updates from apache-snapshots
[INFO] snapshot org.apache.geronimo.plugins:system-database:2.2-SNAPSHOT: checking for updates from codehaus-snapshots
rather than using the system-database pom in the local project it is downloading the obsolete snapshot.
I've worked around this by uploading the system-database pom by hand.
I may try to write a sample project but since seeing the bug depends on having a deployed snapshot and then changing it locally I have no idea how to write an automated test.