I've been working on an application for analyzing p2 repository
quality, primarily with a focus on the release train repository.
It generates a report with detailed information about the
contents and quality of one or more repositories as documented
here:
https://wiki.eclipse.org/Oomph_Repository_Analyzer
My primary concern at this point is to eliminate invalid licenses
so that users aren't prompted to approve multiple slightly
different variants of the same license. My secondary concern is to
eliminate unsigned content; this too is something for which the
user is prompted. Both of these things present to the outside
world an unprofessional impression of our releng processes. A
nice-to-have would be if everyone provided pack200 artifacts,
where appropriate, because this will speed up the
installation/update process for our community (and it is a
requirement for being on the train). Look at the last section of
the report for these details.
The following are the reports for 2019-09 M3:
https://download.eclipse.org/oomph/archive/reports/download.eclipse.org/releases/2019-09/https___download.eclipse.org_technology_epp_packages_2019-09_M3.html
https://download.eclipse.org/oomph/archive/reports/download.eclipse.org/releases/2019-09/http___download.eclipse.org_releases_2019-09_201908301000.html
The primary source of bad licenses at this point is unfortunately
the central license repository itself. This issue will be
addressed by the following Bugzilla:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=537927
To address the problems in the EPP repo, I've open the following
Bugzilla with a Gerrit commit to fix all the problems:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=550628
That in combination with the fix to the central license
repository will make it clean; I've verified that against the
Gerrit build results.
Unfortunately the release train repo is is rough shape and I will
not personally (like I did for the platform EPP) be able to fix
all these problems.
If you look at the report yourself (and please do), and your
features or products are not in one of the valid groups (and not
in the blue circled group which will be fixed when the central
license repo is fixed and you create a new build using that fixed
repo), then you need to take action:

Also please look at the unsigned content:

Please fix your build to sign the content; it's a requirement for
being on the train. Looking at some of the build dates though, I'm
concerned that folks aren't really actively participating.
Thanks in advanced for helping to improve the quality of our
releases.