Hi Kenneth
...
It is bar #8 that is the incomplete bar in the first repeat volta,
...
Two possibilities:
a) ignore the warning, since it compiles OK;
b) Change the measure length for each voice for this specific measure:
\set Timing.measureLength = #(ly:make-moment 2/8)
HTH, cheers,
Pierre
…or you could work around the problem by starting the repeat at the beginning of the first full bar, and including the E and D# lead-in at the end of bar 8.
Or you could make bar 8 a 2/8 bar.
The former would be easier to read, IMHO, but I’m (very much) an amateur musician!
Michael