VCS annotation version does not match app version

[rhblind]

The automatic org.opencontainers.image.version label is not set to the actual application version (found in <appname>.app.src or mix.exs).
The annotation should match the "version of the packaged application" as per the OCI spec.

[rhblind]

Semantic considerations for org.opencontainers.image.version

Before implementing a fix, there's a semantic question to resolve.

In Erlang/OTP, we have two distinct version concepts:

1. Application version (.app.src) - e.g., {vsn, "1.0.0"}
2. Release version (relx config) - e.g., {release, {myapp, "2.0.0"}, [...]}

These can differ. A release bundles multiple applications and has its own version independent of any single app.

The question

When building an OCI image of a release, should org.opencontainers.image.version reflect:

• The main application's version?
• The release's version?

The OCI spec defines this annotation as "version of the packaged software" - but in our context, is the "packaged software" the application or the release?

Options

Approach	Source	Pros	Cons
App version	.app.src	Always concrete	May not match release version
Release version	relx config	Matches release identity	Can be symbolic (semver, git)
Resolved release	relx at build time	Most accurate	Harder to obtain from rebar state

Current draft fix

The current fix on branch 16-vcs-annotation-version-does-not-match-app-version uses the app version from .app.src via rebar_app_info:original_vsn/1, which ensures we always get a concrete version string rather than symbolic refs.

However, if release version is semantically more correct, we could:

1. Use release version when it's an explicit string (e.g., "1.0.0")
2. Fall back to app version when it's symbolic (semver, git)