Try wrapping everything in a toolchain, as defined in (gnu packages
commencement). Then you'll have the ld-wrapper you need and everything

(define-public gm2-toolchain
  (make-gcc-toolchain gm2))

or even

(define-public gm2-toolchain
  (package
    (inherit (make-gcc-toolchain gm2))
    (synopsis (package-synopsis gm2))
    (description (package-description gm2))))

-- 
Efraim Flashner   <efraim@flashner.co.il>   אפרים פלשנר
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