Include associated RethinkDB version with "Data version not recognized" error

[chrisfosterelli]

I was just helping someone debug the following error:

error: Data version not recognized. Is the data directory from a newer version of RethinkDB? (version on disk: 6)

As a RethinkDB user not familiar with the core, "6" doesn't mean anything useful to me and the client could not remember what version of RethinkDB they were using previously.

I was able to track it down here, but I realized it would be very useful as a developer if RethinkDB also included in matching RethinkDB version.

Possibly like so:

error: Data version not recognized. Is the data directory from a newer version of RethinkDB? 
Version on disk: 6 (matches with RethinkDB 2.1)

This is potentially related to #2657, but it looks like the issue was considered resolved there.

[danielmewes]

Thanks for opening an issue @chrisfosterelli .

The problem is that RethinkDB only stores the version in a numeric form (as a 6 in this case). So an old version of RethinkDB has no idea which actual RethinkDB version this number corresponds to and how to print it.

We will need to change the disk format to include a plaintext representation of the version to improve this. It's a little bit of work, but can be done.

[chrisfosterelli]

Ah, right that makes sense. Thanks for the quick response, hopefully this can be added at some point in the future.