Exception for math.log/2 on complex, imaginary part

Math

\[\frac{\tan^{-1}_* \frac{im}{re} \cdot \log base - \log \left(\sqrt{re \cdot re + im \cdot im}\right) \cdot 0.0}{\log base \cdot \log base + 0.0 \cdot 0.0}\]

C

double f(double re, double im, double base) {
        double r40147 = im;
        double r40148 = re;
        double r40149 = atan2(r40147, r40148);
        double r40150 = base;
        double r40151 = log(r40150);
        double r40152 = r40149 * r40151;
        double r40153 = r40148 * r40148;
        double r40154 = r40147 * r40147;
        double r40155 = r40153 + r40154;
        double r40156 = sqrt(r40155);
        double r40157 = log(r40156);
        double r40158 = 0.0;
        double r40159 = r40157 * r40158;
        double r40160 = r40152 - r40159;
        double r40161 = r40151 * r40151;
        double r40162 = r40158 * r40158;
        double r40163 = r40161 + r40162;
        double r40164 = r40160 / r40163;
        return r40164;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019323 +o rules:numerics
(FPCore (re im base)
  :name "math.log/2 on complex, imaginary part"
  :precision binary64
  (/ (- (* (atan2 im re) (log base)) (* (log (sqrt (+ (* re re) (* im im)))) 0.0)) (+ (* (log base) (log base)) (* 0.0 0.0))))

Backtrace

get-representation: Unknown representation real		L	C
(unnamed)	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt	65	3
filter	/opt/racket-7.2/collects/racket/private/list.rkt	256	2
infer-splitpoints	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt	34	0
get-final-combination	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt	369	0
(unnamed)	/opt/racket-7.2/collects/racket/private/more-scheme.rkt	261	28
run	/opt/racket-7.2/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.2/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.2/collects/racket/private/more-scheme.rkt	261	28