If I bench my code with nim c it works, but if I compile with nim cpp I get this error.

/home/jack/.cache/nim/benchmark_r/@mbenchmark.nim.cpp: In function ‘tyTuple__YMUa8EyOXmFxxl9adnwkkgA executeX60gensym11___benchmark_39(NI)’:
/home/jack/.cache/nim/benchmark_r/@mbenchmark.nim.cpp:262:25: error: ‘doNotOptimizeAway’ was not declared in this scope
  262 |                         doNotOptimizeAway((&r));
      |                         ^~~~~~~~~~~~~~~~~
/home/jack/.cache/nim/benchmark_r/@mbenchmark.nim.cpp: In function ‘tyTuple__YMUa8EyOXmFxxl9adnwkkgA executeX60gensym14___benchmark_68(NI)’:
/home/jack/.cache/nim/benchmark_r/@mbenchmark.nim.cpp:285:25: error: ‘doNotOptimizeAway’ was not declared in this scope
  285 |                         doNotOptimizeAway((&r));

Using current version of Nim

Z:\Work\nim>nim --version
Nim Compiler Version 0.19.1 [Windows: amd64]
Compiled at 2018-10-10
Copyright (c) 2006-2018 by Andreas Rumpf

git hash: 16a941a64206d7727cd1971559bfeea70ccc952f
active boot switches: -d:release

Using current Nimbench

Z:\Work\nim>nimble list --installed
nimbench [0.2.0]
nimr [0.1.0]
regex [0.8.1]
strfmt [0.9.1]
unicodedb [0.6.0]
unicodeplus [0.4.0]

Running nimbench demo

as per http://htmlpreview.github.io/?https://github.com/ivankoster/nimbench/blob/master/nimbench.html
Z:\Work\nim_work>nim c -r test_nimbench.nim
Hint: used config file 'Z:\work\nim\config\nim.cfg' [Conf]
Hint: system [Processing]
Hint: test_nimbench [Processing]
Hint: nimbench [Processing]
Hint: strutils [Processing]
Hint: parseutils [Processing]
Hint: math [Processing]
Hint: bitops [Processing]
Hint: algorithm [Processing]
Hint: unicode [Processing]
Hint: strfmt [Processing]
Hint: macros [Processing]
Hint: streams [Processing]
......\C:\Users\DM.nimble\pkgs\strfmt-0.9.1\strfmt.nim(528, 25) Error: type mismatch: got <tuple of (FmtType, int, int, nil, FmtAlign, FmtSign, bool, bool, bool, nil)> but expected 'Format = tuple[typ: FmtType, precision: int, width: int, fill: string, align: FmtAlign, sign: FmtSign, baseprefix: bool, upcase: bool, comma: bool, arysep: string]'

Could it be relate to:

Broken in current Nim devel
https://bitbucket.org/lyro/strfmt/issues/16/broken-in-current-nim-devel