Running Minizinc model produces unknown error

Question

I am a beginner with minizinc and optimization. I am trying to flesh out a curve of points where only average decile statistics are available.

Here is my model:

array[1..10] of float: deciles;
deciles=[0.01469197, 0.02633663, 0.03507719, 0.04723933, 0.05927129, 0.07852426, 0.09907269, 0.12420518, 0.19467811, 0.60604946];

float:maxa=10.0;
float:maxb=20.0;
float:maxc=10.0;
float:maxd=200.0;
var 0..maxa: a;
var 0..maxb: b;
array[1..1000] of var 0..maxc: c;
array[1..1000] of var 0..maxd: d;

constraint forall(k in 1..1000) (d[k]=a*pow(int2float(k)/10,2)+b*int2float(k)/10+c[k]);

constraint forall(i in 1..10) (sum(j in (i-1)*100+1..i*100) (d[j]) = deciles[i]*100);
solve minimize max(c)-min(c);
output[show(max(c)-min(c))];

I thought this would be an easy model to start with, but when running from the minizinc IDE (gecode solver) I get the following output:

Compiling IstanbulDeciles.mzn
Running IstanbulDeciles.mzn
Command line:
fzn-gecode -s "/tmp/MiniZinc IDE-6zuoJB/IstanbulDeciles.fzn"

followed by a popup with the caption:

"Unknown error while executing the MiniZinc interpreter."

All of the other failures I've encountered so far have produced indicators as to what went wrong, but I haven't a clue where to start with this one. Can anyone help or point out where I've gone wrong?