This got lost when I converted from releaseTools.nixBuild to stdenv.mkDerivation. Doh!
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P3M6UFMPTIF7TPCFZHRDFX4MTXB6NZWT3ZFUEIC5VMNM55E7EIKAC
T4LLYESZ2HUXSLKZ6GNBLVWUVG7R5IDFHYHYO773QIZ6QTOOXR2AC
doCheck = true;