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

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2022203 
(FPCore (x)
  :name "Numeric.Integration.TanhSinh:nonNegative from integration-0.2.1"
  :precision binary64
  (/ x (- 1.0 x)))

Backtrace

hash-ref: no value found for key key: '~LC
get-parametric-operator/data/pavpan/nightlies/herbie/enumo-rat/src/syntax/syntax.rkt2180
f336.../match/compiler.rkt54840
expand-parametric/data/pavpan/nightlies/herbie/enumo-rat/src/syntax/sugar.rkt620
(unnamed)/data/pavpan/nightlies/herbie/enumo-rat/src/syntax/rules.rkt1768
generate-rules-for/data/pavpan/nightlies/herbie/enumo-rat/src/syntax/rules.rkt1610
generate-missing-rules/data/pavpan/nightlies/herbie/enumo-rat/src/syntax/rules.rkt1870
(unnamed)/data/pavpan/nightlies/herbie/enumo-rat/src/syntax/rules.rkt2926
get-swaps/data/pavpan/nightlies/herbie/enumo-rat/src/symmetry.rkt60
connected-components/data/pavpan/nightlies/herbie/enumo-rat/src/symmetry.rkt170
run-improve!/data/pavpan/nightlies/herbie/enumo-rat/src/mainloop.rkt2960
(unnamed)/data/pavpan/nightlies/herbie/enumo-rat/src/sandbox.rkt556
(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