ArcPy spatial join stops without error

I am trying to run a spatial join on ArcPy. The files are quite large, and I am running the code in Idle. The code seems to "stop" without producing an error.

My code is as follows:

a = shapefile1.shp
b = Default.gdbshapefile2
y = shapefile2.shp
arcpy.SpatialJoin_analysis(a, b, y, "JOIN_ONE_TO_MANY", "KEEP_ALL")
print("finished join 1")

The code stops without printing "finished join 1". However it does not produce an error. I am not sure if it finishes the join either, it produces a large file, but I have no way of checking if it is complete.