See the 2022 Blockly Developer Summit site here.

Closure Library

Did you just get this error message?

If so, then you are probably attempting to run or build the uncompressed version of Blockly and you are missing the dependency on Closure Library.

Getting Closure

Getting Closure from GitHub is quick and easy:

Download ZIP File Download TAR Ball View On GitHub

Once you have the Closure files, place them next to Blocky's root directory and ensure that the directory is named closure-library. This is the directory structure you want:

That's it. Blockly should now build and work in uncompressed mode.