The second beta's preparation pull request failed Backend tests
(TestCurrentPrereleasePacketTracksInstallMetadata): the changelog the
release metadata tool wrote said it describes the changes since
v6.6.0-beta.1, and the test expected v6.5.0. previousPrereleaseVersion
only understood -rc.N, so for beta.2 it reported no predecessor and the
test fell back to the previous stable. The tool names the predecessor in
the pre-release's own stage, alpha, beta or rc, N-1.
Do the same in the helper: rc.2 follows rc.1 and beta.2 follows beta.1,
while the first of a stage has no predecessor even when an earlier stage
shipped. Pin it with a table test, because beta.1 passed without ever
exercising the second-beta case.
Run against the beta.2 preparation snapshot with this change, the whole
installer test package and the release policy suite pass.
Contract-Neutral: Test helper only; no release, install or customer contract changes.
rcourtman
7673e8bc10