+(define (make-session-variable name value)
+ (if (ly:undead? lilypond-declarations)
+ (ly:error (_ "define-session used after session start")))
+ (let ((var (module-make-local-var! (current-module) name)))
+ (if (variable-bound? var)
+ (ly:error (_ "symbol ~S redefined") name))
+ (variable-set! var value)
+ var))
+
+(defmacro define-session (name value)