Manifestation to JSON fails to properly escape object keys

[fare]

The quote there should be escaped, but isn't:
'{ "a\"b" : "1" }' | jsonnet - ==>

{
   "a"b": "1"
}

[fare]

Thanks for a prompt fix!

(I don't actually need this capability right now; I was just exploring what was the exact syntax of identifiers used to access terraform remote state, and stumbled upon that bug in jsonnet.)