ipfs get $hashofblock gives confusing error message

[jonnor]

When the hash referred is a block, one cannot use ipfs get (as it expects a file object) - but instead have to use ipfs block get. This is fine, but the error message when attempting is not very helpful in understanding this:

$ ipfs get QmSnWHYwDUE1gdcUb6ZYgU2khZ5FkxuWsTvXbw3zGsKc3x
Error: Failed to decode Protocol Buffers: incorrectly formatted merkledag node: Unmarshal failed. proto: illegal wireType 6

$ ipfs block get QmSnWHYwDUE1gdcUb6ZYgU2khZ5FkxuWsTvXbw3zGsKc3x
�ripld-image-version�htilesize�ax��ay��etiles�ax�ay�flevel0��fformatcpngdsize�ax��ay��ddata���
......

Expected would be something like "Requested hash $hash refers to a block, not an object. Use ipfs block get instead". Possibly with the detailed error message above following it.

Ping @Kubuxu

[Kubuxu]

All files are blocks, in this case the block just doesn't contain unixfs format.

It should be more of: "Requested hash isn't recognised unix file encoding format" or something similar.
If someone has good error message, it should be quite easy to implement.

[whyrusleeping]

It looks like the block you requested is not a merkledag object. We should fix the error messages, and increase documentation around the layers of data involved here. raw blocks, merkledag protobufs, and then unixfs protobufs

[jonnor]

It is the kind of "block" one gets with ipfs.block.put using HTTP API. I guess that is a "raw block"?
Some guidance around this when making use of the API would indeed have been helpful, it is quite possible I should not have been using the block method/endpoint in the first place...
Was uploading a Buffer representing a PNG in one case, and a CBOR serialized JSON in another case.

[whyrusleeping]

@jonnor would the following look good to you?

➜  go-ipfs git:(master) ✗ ipfs object get QmUJPTFZnR2CPGAzmfdYPghgrFtYFB6pf1BqMvqfiPDam8
Error: QmUJPTFZnR2CPGAzmfdYPghgrFtYFB6pf1BqMvqfiPDam8 was not a valid merkledag node

[jonnor]

Not a merkledag node does not explain to me that it is a block, or help me understand that I should be using block...

[whyrusleeping]

@jonnor well, everything is technically a block. The cause of the error is that its not a merkledag node. You can do a block get on a perfectly valid merkledag

[RichardLitt]

If everything is a block, then why isn't ipfs block named ipfs merkledagNode?

[Kubuxu]

@RichardLitt because ipfs block deals with raw blobs stored in IPFS. ipfs object deals with DAG nodes and ipfs get interprets DAG nodes as files.

[RichardLitt]

ipfs block - Manipulate raw IPFS blocks.

Should this be 'raw IPFS MerkleDag blocks`, maybe?

[Kubuxu]

No ipfs object manipulates MerkleDags. ipfs block is for binary data not interpreted by IPFS in any way.

[Kubuxu]

All files built from objects, and all objects built from blocks.

[whyrusleeping]

@jonnor how about "The block referred to by was not a valid merkledag node" ?