mit-scheme-release-10.1.10 and "release-10" branch from the Savannah repo:
1 ]=> (vector 1 2)
;Value:
;Unbound variable: nmv-header?
;To continue, call RESTART with an option number:
; (RESTART 2) => Define nmv-header? to a given value.
; (RESTART 1) => Return to read-eval-print level 1."master" branch doesn't build, neither does mit-scheme-release-10.1.9.