In the online docs for the Esquilo library, in the links on the left we see "Capture". The heading in the title is "CAPTURE". The example on the right instantiates a class instance using all lower case "capture". This causes all ends of grief.
Given case sensitivity, I think that these should all be consistent.
Using the example on the right:
local capture_dist = capture(0);
%%Runtime error [the index 'capture' does not exist]
Followup - I figured it out. It must be
Although I don't understand why if the "require" can't be met it doesn't throw an error there instead of when attempting to access a library member.