2frac (problem 3.3.1)

Specification

?
\[\begin{array}{l} \\ \frac{1}{x + 1} - \frac{1}{x} \end{array} \]
(FPCore (x) :precision binary64 (- (/ 1.0 (+ x 1.0)) (/ 1.0 x)))
double code(double x) {
	return (1.0 / (x + 1.0)) - (1.0 / x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (1.0d0 / (x + 1.0d0)) - (1.0d0 / x)
end function
public static double code(double x) {
	return (1.0 / (x + 1.0)) - (1.0 / x);
}
def code(x):
	return (1.0 / (x + 1.0)) - (1.0 / x)
function code(x)
	return Float64(Float64(1.0 / Float64(x + 1.0)) - Float64(1.0 / x))
end
function tmp = code(x)
	tmp = (1.0 / (x + 1.0)) - (1.0 / x);
end
code[x_] := N[(N[(1.0 / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(1.0 / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{x + 1} - \frac{1}{x}
\end{array}

Reproduce

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herbie shell --seed 2024005 
(FPCore (x)
  :name "2frac (problem 3.3.1)"
  :precision binary64
  (- (/ 1.0 (+ x 1.0)) (/ 1.0 x)))

Please file a bug report with this information.

Backtrace

repr->cost: arity mismatch; the expected number of arguments does not match the given number expected: 2 given: 1LC
loop.../private/map.rkt5419
f490.../match/compiler.rkt54840
loop.../private/map.rkt5419
f490.../match/compiler.rkt54840
make-alt-table/home/nightlies/herbie/platforms/src/core/alt-table.rkt400
(unnamed)/usr/share/racket/collects/racket/contract/private/arrow-val-first.rkt48618
initialize-alt-table!/home/nightlies/herbie/platforms/src/mainloop.rkt3160
mutate!/home/nightlies/herbie/platforms/src/mainloop.rkt3520
run-improve!/home/nightlies/herbie/platforms/src/mainloop.rkt3380
get-alternatives/report/home/nightlies/herbie/platforms/src/sandbox.rkt1690
(unnamed)/home/nightlies/herbie/platforms/src/sandbox.rkt2626
(unnamed)/usr/share/racket/pkgs/profile-lib/main.rkt4010
profile-thunk/usr/share/racket/pkgs/profile-lib/main.rkt90
(unnamed)/usr/share/racket/collects/racket/engine.rkt4224