ipfs/kubo · error

got unexpected output from util.RmBlocks

Error message

got unexpected output from util.RmBlocks

What it means

CoreAPI's block rm implementation iterates the channel returned by util.RmBlocks and expects every non-nil item to be a *util.RemovedBlock. If the channel yields any other type, this error is returned. It indicates an unexpected internal result type from the block-removal utility — typically a kubo/boxo version skew or a bug, not user input.

Source

Thrown at core/coreapi/block.go:119

		return err
	}
	cids := []cid.Cid{rp.RootCid()}
	o := util.RmBlocksOpts{Force: settings.Force}

	out, err := util.RmBlocks(ctx, api.blockstore, api.pinning, cids, o)
	if err != nil {
		return err
	}

	select {
	case res, ok := <-out:
		if !ok {
			return nil
		}

		remBlock, ok := res.(*util.RemovedBlock)
		if !ok {
			return errors.New("got unexpected output from util.RmBlocks")
		}

		if remBlock.Error != nil {
			return remBlock.Error
		}
		return nil
	case <-ctx.Done():
		return ctx.Err()
	}
}

func (api *BlockAPI) Stat(ctx context.Context, p path.Path) (coreiface.BlockStat, error) {
	ctx, span := tracing.Span(ctx, "CoreAPI.BlockAPI", "Stat", trace.WithAttributes(attribute.String("path", p.String())))
	defer span.End()

	rp, _, err := api.core().ResolvePath(ctx, p)
	if err != nil {
		return nil, err

View on GitHub (pinned to 329838acdf)

Solutions

1. Rebuild against the pinned dependencies (make build; do not use a local boxo replace directive)
2. Update or downgrade to an official kubo release where RmBlocks returns *util.RemovedBlock
3. If reproducible on a stock build, file a bug with the kubo repository including the CID and command used
4. As a workaround, remove blocks via 'ipfs repo gc' if appropriate

remBlock, ok := res.(*util.RemovedBlock); !ok // skip -> error path already in library

err := api.Block().Rm(ctx, path, opts...)
if err != nil && strings.Contains(err.Error(), "got unexpected output from util.RmBlocks") {
    return fmt.Errorf("internal block rm failure; rebuild with pinned deps: %w", err)
}
return err

When it happens

Trigger: Calling 'ipfs block rm' (RPC block/rm) when the underlying util.RmBlocks emits a value that is neither nil nor *util.RemovedBlock, e.g. after swapping boxo/go-blockservice versions where the result type changed.

Common situations: Running a kubo build with a manually pinned, incompatible boxo commit; custom plugins or forks altering the blockservice removal path; hitting a genuine upstream bug in a development build.

Related errors

• pin check failed: %w
• ipfs api address could not be found
• unexpected redirect
• unsupported file type '%s'
• cannot parse mode %s: %s

AI-assisted analysis of ipfs/kubo@329838acdf (2026-09-03). Data as JSON: /api/errors/4253b5227240a200. Report an issue: GitHub.