I remember that this package is already present in the previous LSST Kernel. In fact when I try to install it from the new Lsst Kernel this is the message i receive:
Defaulting to user installation because normal site-packages is not writeable
Requirement already satisfied: gatspy in /data0/sw.tmpfs/anaconda3/lib/python3.8/site-packages (0.3)
but when I type import gatspy
ModuleNotFoundError: No module named 'gatpsy'