Thread:Extension talk:Lingo/Composer fails

I just tried installing this extension through Composer, but every attempt fails with "UnexpectedValueException" ("Could not parse version constraint *", likewise for dev-master).

Some alternative syntax I tried
 * Putting a double colon between package and version (per instructions for the Chameleon skin), but no luck: [Invalid Argument Exception] ("could not find package * with any version for your minimum stability (stable)").
 * Likewise, ":~". No luck.
 * replacing single quotes with double quotes. To no avail.
 * Using quotes around the package as well. Again, no luck.

I'm at a loss here. Could there be something wrong with the download location?