Joblib UserWarning while trying to cache results

Question

I get the following UserWarning when trying to cache results using joblib:

from tempfile import mkdtemp
cachedir = mkdtemp()
from joblib import Memory
memory = Memory(cachedir=cachedir, verbose=0)

@memory.cache
def get_nc_var3d(path_nc, var, year):
    """
    Get value from netcdf for variable var for year
    :param path_nc:
    :param var:
    :param year:
    :return:
    """
    try:
        hndl_nc = open_or_die(path_nc)
        val = hndl_nc.variables[var][int(year), :, :]
    except:
        val = numpy.nan
        logger.info('Error in getting var ' + var + ' for year ' + str(year) + ' from netcdf ')
    
    hndl_nc.close()
    return val

I get the following warning when calling this function using parameters:

UserWarning: Persisting input arguments took 0.58s to run.
If this happens often in your code, it can cause performance problems 
(results will be correct in all cases). 
The reason for this is probably some large input arguments for a wrapped function (e.g. large strings).
THIS IS A JOBLIB ISSUE. If you can, kindly provide the joblib's team with an example so that they can fix the problem.

Input parameters: C:/Users/rit/Documents/PhD/Projects/\GLA/Input/LUWH/\LUWLAN_v1.0h\transit_model.nc range_to_large 1150

How do I get rid of the warning? And why it is happening, since the input parameters are not too long.