DEBUG=0 did not make a difference for our build.  perhaps it was already off by default.
our TORCH_CUDA_ARCH_LIST is "5.2;6.1;7.0;7.5+PTX"
as an experiment, I removed 5.2 and the size went from 2.5GB to 2.4GB.
then removed 7.0 to go to 2.3GB
I did notice that cuda libraries got much larger between cuda 10.2 to 11 which is what revealed the size issues.  But I’ll need to see if nividia has anything to say about that.