Error in scipy curve_fit when using absolute_sigma

I have this code:

import numpy as np
from scipy.optimize import curve_fit

def lin_func(x, a, b):
    return a * x + b

a = 0.005/4
b = 10000/4
N = 10000

position_list = np.array([-100,-50,-20,0,20,50,100]) 

def get_params(N):
    counts_list = np.zeros(len(position_list))
    for i in range(len(position_list)):
        position_0 = position_list[i]
        counts = 0
        for j in range(N):
            position = np.random.normal(position_0,10)
            p = 0.5+a+b*position*10**(-6) 
            counts = counts + np.sum(np.random.binomial(1000, p, 1)) 
        counts_list[i] = counts
    print(np.sqrt(counts_list))
    popt, pcov = curve_fit(lin_func, position_list*10**(-6), counts_list, absolute_sigma = np.sqrt(counts_list))
    return popt[1]/(N*1000)

K = 100
params_list = np.zeros(K)
for i in range(K):
    params_list[i] = get_params(N)-0.5
    print(params_list[i])

When I run it, it runs ok for a while, but then it displays this error:

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

This only happens if I add absolute_sigma = np.sqrt(counts_list) to the function call, however if I print counts_list I don't see anything wrong with the number, just before the error pops up (they seem similar to the values printed when the function call works just fine). I am not sure how to debug this.

This is the full error message:

ValueError                                Traceback (most recent call last)
Cell In[10], line 4
      2 params_list = np.zeros(K)
      3 for i in range(K):
----> 4     params_list[i] = get_params(N)-0.5
      5     print(params_list[i])

Cell In[9], line 13, in get_params(N)
     11     counts_list[i] = counts
     12 print(np.sqrt(counts_list))
---> 13 popt, pcov = curve_fit(lin_func, position_list*10**(-6), counts_list, absolute_sigma = np.sqrt(counts_list))
     14 return popt[1]/(N*1000)

File ~/miniforge3/lib/python3.10/site-packages/scipy/optimize/_minpack_py.py:897, in curve_fit(f, xdata, ydata, p0, sigma, absolute_sigma, check_finite, bounds, method, jac, full_output, **kwargs)
    895     pcov.fill(inf)
    896     warn_cov = True
--> 897 elif not absolute_sigma:
    898     if ysize > p0.size:
    899         s_sq = cost / (ysize - p0.size)

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

Take another look at the curve_fit docstring. absolute_sigma is expected to be a boolean parameter. I suspect you meant to set the parameter sigma, not absolute_sigma.