[cross-project-issues-dev] Why Can't 'osgi.service; (objectClass=org.osg

[Ed Merks <ed.merks@xxxxxxxxx>]

Does anyone know why we might encounter failures like this:

  ERROR: org.eclipse.equinox.p2.director code=10053 Cannot complete the 
install because one or more required items could not be found.
    ERROR: org.eclipse.equinox.p2.director code=0 Software being 
installed: artificial_root 1.0.0.v1553184475173
    ERROR: org.eclipse.equinox.p2.director code=0 Missing requirement: 
Eclipse UI Application Services 1.3.400.v20190212-2214 
(org.eclipse.e4.ui.services 1.3.400.v20190212-2214) requires 
'osgi.service; (objectClass=org.osgi.service.event.EventAdmin)' but it 
could not be found
    ERROR: org.eclipse.equinox.p2.director code=1 Cannot satisfy 
dependency:
      ERROR: org.eclipse.equinox.p2.director code=0 From: 
artificial_root 1.0.0.v1553184475173
      ERROR: org.eclipse.equinox.p2.director code=0 To: 
org.eclipse.equinox.p2.iu; org.eclipse.platform.feature.group 0.0.0
    ERROR: org.eclipse.equinox.p2.director code=1 Cannot satisfy 
dependency:
      ERROR: org.eclipse.equinox.p2.director code=0 From: Eclipse 4 
Rich Client Platform 1.6.400.v20190305-0602 
(org.eclipse.e4.rcp.feature.group 1.6.400.v20190305-0602)
      ERROR: org.eclipse.equinox.p2.director code=0 To: 
org.eclipse.equinox.p2.iu; org.eclipse.e4.ui.services 
[1.3.400.v20190212-2214,1.3.400.v20190212-2214]
    ERROR: org.eclipse.equinox.p2.director code=1 Cannot satisfy 
dependency:
      ERROR: org.eclipse.equinox.p2.director code=0 From: Eclipse 
Platform 4.11.0.v20190307-0500 (org.eclipse.platform.feature.group 
4.11.0.v20190307-0500)
      ERROR: org.eclipse.equinox.p2.director code=0 To: 
org.eclipse.equinox.p2.iu; org.eclipse.rcp.feature.group 
[4.11.0.v20190307-0500,4.11.0.v20190307-0500]
    ERROR: org.eclipse.equinox.p2.director code=1 Cannot satisfy 
dependency:
      ERROR: org.eclipse.equinox.p2.director code=0 From: Eclipse RCP 
4.11.0.v20190307-0500 (org.eclipse.rcp.feature.group 4.11.0.v20190307-0500)
      ERROR: org.eclipse.equinox.p2.director code=0 To: 
org.eclipse.equinox.p2.iu; org.eclipse.e4.rcp.feature.group 
[1.6.400.v20190305-0602,1.6.400.v20190305-0602]

I have this problem resolving the a target platform using Oomph's 
Targlets against 2019-03, but users are reporting what's essentially the 
same error/cause trace when trying to update from Eclipse 2018-12 to 
2019-03:

https://www.eclipse.org/forums/index.php/mv/msg/1098132/1804241/#msg_1804241