Merge Evidence

DC-22 (0.15.0) adds prikk merge-evidence, the first public read-only UX over the DC-21 merge/conflict evidence vocabulary. DC-23 (0.16.0) stabilizes its text output.

For the current concepts behind operation ordering, commutation, confluence, evidence outcomes, reason codes, and proof phases, see Patch Algebra and Merge Evidence.

For the planning classification layer over the same explicit-input evidence, see Merge Plan. Neither command executes a merge — for that, see Merge (DC-74), which reuses this same evidence to decide whether to seal.

prikk merge-evidence \
  --baseline-block BLOCK \
  (--left-block BLOCK | --left-ref REF) \
  (--right-block BLOCK | --right-ref REF) \
  [path]

The command derives the single-parent candidate sequences from an explicit sealed baseline to two explicit left/right targets, runs the read-only merge/conflict evidence analysis, and prints the resulting report.

Selector rules:

• --baseline-block is required and names the sealed baseline block.
• Each side must choose exactly one selector: --left-block or --left-ref, and --right-block or --right-ref.
• A --left-ref/--right-ref value may name a received ref (remotes/<name>, DC-85), previewing evidence against imported history exactly as it would for a local branch. This is read-only, so a preview can name a remotes/ ref on either side even though prikk merge itself never accepts one as --into — the preview does not claim the plan it shows is executable as-is.
• The optional positional argument is the repository root, as with other commands. It is not a path filter.

The command is read-only. It does not infer merge bases, execute merges, publish merge commits, write refs or WAL records, materialize worktree conflicts, or persist proof/witness objects.

Output

Output is text-only and intended for human diagnostics. It is not a durable machine-readable schema. DC-23 makes the shape easier to scan:

merge evidence
baseline block: <block-id>
left selector: ref heads/topic-a
left target block: <block-id>
left operations: 3
right selector: block <block-id>
right target block: <block-id>
right operations: 2
outcome: Conflict
reason: pair_conflict
items: 1 displayed of 1

cross:
  left[0] op_seq=1 ChangePerm src/lib.rs
  right[0] op_seq=1 ChangePerm src/lib.rs
  outcome: Conflict
  reason: pair_conflict
  phase: classification

note: read-only evidence; no merge commit, ref update, WAL write, or worktree change was performed

Reading the output:

• both sides show the submitted selector text and the resolved target block identity;
• left and right operation counts are shown separately;
• the full-report outcome and reason are shown before item details, and are computed over the full candidate sequences;
• items: N displayed of N reports the displayed and total item counts (equal in this release; DC-23 adds no display filtering);
• cross-side items render as a cross: block with separate left[...] and right[...] operation lines, rather than an ambiguous one-line form;
• when a side changes one file more than once (any mix of edits, permission changes and binary replacements, optionally ending in a delete, or a new text file followed by edits), the evidence judges that run by its net effect from the baseline, and uses it only when replaying it reproduces the side exactly. An operation line for such a run names its first operation and adds folded-through=left[N] op_seq=M for its last; a run whose net effect is a mode change and an edit shows both operations with the same range. Indices and counts are always those of the original sequence;
• report-level items render as report: without a fake operation label;
• DC-21 outcome and reason-code names are preserved exactly;
• a RenamePath operand’s line also carries asserted-by=<key-id> — the patch’s AUTHOR signature key id. This is structural, not a rendering choice: the underlying read type cannot represent a rename without its asserting signer, so a patch whose AUTHOR signature is missing fails the command rather than showing a rename with no signer.

Privacy: the output never includes raw text spans, replacement text, blob bytes, absolute host paths, .prikk private paths, signer secrets, key material, or arbitrary object debug dumps. Displayed paths are repository-relative.

Exit Status

Process success is independent of the evidence outcome: a produced report exits 0 even when the outcome is Conflict.

Deferred

prikk merge (DC-74) executes confluent merges — see the merge guide; this command stays read-only regardless. Still deferred:

• conflict resolution;
• automatic merge-base discovery;
• branch merge semantics beyond a two-sided confluent merge;
• display-path filtering and scoped/path-limited merge analysis;
• persisted proof/witness/merge-evidence objects;
• JSON or other machine-readable output;
• public prikk-replay API stabilization.