LTspice: when I turn a schematic into a subcircuit it behaves differently. Why?
To answer my own question: it seems LTspice requires text files to be saved with Windows Latin 1 code page, CRLF line endings. I'm using Wine on a Mac, and my text-editor saves as UTF-8 by default. I'm guessing LTspice misinterprets the UTF-8 µ on capacitor values as something invalid, but confusingly doesn't throw an error message.