Problem with "-e" (execute Scheme code) option

[Alan Stern]

The "-e" command line option (execute Scheme code) doesn't work right.
The code gets executed twice(!) and the results aren't available during
the remainder of the Lilypond run -- which makes the facility useless.

Here's an example with 2.7.33 (behavior under 2.7.37 is the same, but
I can't run the later version on this machine):

$ cat a.ly
\version "2.7.33"

#(display "Value of a: ")
#(display a)
#(newline)
$ lilypond -e '(define a 42) (display "hello") (newline)' a.ly
GNU LilyPond 2.7.33
hello
hello
Processing `a.ly'
Parsing...Value of a: ERROR: Unbound variable: a
Segmentation fault
$