Content-Length is the number of bytes in the message, but the JSONRPC
code was interpreting it as a number of characters (when both reading and
writing), which caused it to fail on multibyte UTF-8 characters.
`blueprint-compiler port` interactively ports a project to blueprint.
It will create the subproject wrap file, add it to .gitignore, decompile
your GtkBuilder XML files, emit code to copy and paste into your
meson.build file, and update POTFILES.in.
It can't quite handle all of the features the forward compiler can, so
it will skip those files.
