pyhst2: FTBFS with CUDA 11: Unsupported gpu architecture 'compute_30'

Imported from Debian bug http://bugs.debian.org/968318:

Source: pyhst2
Version: 2020a-1
Severity: important
Tags: ftbfs
Justification: fails to build from source

Hi,

pyhst2 FTBFS with CUDA 11 in experimental:

   dh_auto_build -O--buildsystem=pybuild
I: pybuild base:217: /usr/bin/python3 setup.py build
running build
running build_ext
building 'PyHST2_2019b/libgputomo' extension
Warning: Can't read registry to find the necessary compiler setting
Make sure that Python modules winreg, win32api or win32con are installed.
C compiler: x86_64-linux-gnu-gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O2 -Wall -g -fstack-protector-strong -Wformat -Werror=format-security -g -fwrapv -O2 -g -O2 -fdebug-prefix-map=/build/pyhst2-2020a=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fPIC

creating build
creating build/temp.linux-x86_64-3.8
creating build/temp.linux-x86_64-3.8/PyHST
creating build/temp.linux-x86_64-3.8/PyHST/Cspace
creating build/temp.linux-x86_64-3.8/PyHST/Cspace/pdwt
creating build/temp.linux-x86_64-3.8/PyHST/Cspace/pdwt/src
compile options: '-I/usr/lib/python3/dist-packages/numpy/core/include -I/usr/include -IPyHST/Cspace -I/usr/include/hdf5/serial/ -I/usr/include/python3.8 -c'
extra options: 'gcc nvcc'
nvcc: PyHST/Cspace/pdwt/src/wt.cu
nvcc: PyHST/Cspace/pdwt/src/common.cu
nvcc: PyHST/Cspace/pdwt/src/utils.cu
nvcc: PyHST/Cspace/pdwt/src/nonseparable.cu
nvcc: PyHST/Cspace/pdwt/src/separable.cu
nvcc: PyHST/Cspace/pdwt/src/haar.cu
nvcc fatal : Unsupported gpu architecture 'compute_30'
nvcc fatal : Unsupported gpu architecture 'compute_30'
mpicc: PyHST/Cspace/pdwt/src/filters.cpp
nvcc fatal : Unsupported gpu architecture 'compute_30'
nvcc: PyHST/Cspace/gputomo.cu
nvcc fatal : Unsupported gpu architecture 'compute_30'
nvcc fatal : Unsupported gpu architecture 'compute_30'
nvcc fatal : Unsupported gpu architecture 'compute_30'
nvcc fatal : Unsupported gpu architecture 'compute_30'
nvcc: PyHST/Cspace/cudamedianfilter.cu
nvcc: PyHST/Cspace/chambollepock.cu
nvcc: PyHST/Cspace/wavelets.cu
nvcc: PyHST/Cspace/sinofilters.cu
nvcc fatal : Unsupported gpu architecture 'compute_30'
nvcc fatal : Unsupported gpu architecture 'compute_30'
nvcc fatal : Unsupported gpu architecture 'compute_30'
nvcc fatal : Unsupported gpu architecture 'compute_30'
error: Command "/usr/bin/nvcc -I/usr/lib/python3/dist-packages/numpy/core/include -I/usr/include -IPyHST/Cspace -I/usr/include/hdf5/serial/ -I/usr/include/python3.8 -c PyHST/Cspace/pdwt/src/common.cu -o build/temp.linux-x86_64-3.8/PyHST/Cspace/pdwt/src/common.o -gencode arch=compute_30,code=compute_30 -gencode arch=compute_50,code=compute_50 --compiler-options -fPIC -O3 -g -D_FORCE_INLINES" failed with exit status 1
E: pybuild pybuild:352: build: plugin distutils failed with: exit code=1: /usr/bin/python3 setup.py build
dh_auto_build: error: pybuild --build returned exit code 13
make: *** [debian/rules:9: build] Error 25

Andreas