Issue with landlab/utils/matrix.py in compilation

I’m updating landlab in advance of addressing this issue in terrainbento TerrainBento/terrainbento/issues/156

I ran into an unexpected issue related to a relatively new bit of cython (the spiffy matrix utils for finite volume solutions).

I’m on master, I’ve updated all the dependencies listed in the requirements-XXX.txt file. After running make clean, I get the following with python setup.py develop

gcc -bundle -undefined dynamic_lookup -L/Users/barnhark/opt/anaconda3/envs/landlab_dev/lib -arch x86_64 -L/Users/barnhark/opt/anaconda3/envs/landlab_dev/lib -arch x86_64 -arch x86_64 build/temp.macosx-10.9-x86_64-3.8/landlab/graph/matrix/ext/at_patch.o -o build/lib.macosx-10.9-x86_64-3.8/landlab/graph/matrix/ext/at_patch.cpython-38-darwin.so
building 'landlab.utils._matrix' extension
creating build/temp.macosx-10.9-x86_64-3.8/landlab/utils
gcc -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I/Users/barnhark/opt/anaconda3/envs/landlab_dev/include -arch x86_64 -I/Users/barnhark/opt/anaconda3/envs/landlab_dev/include -arch x86_64 -I/Users/barnhark/.local/lib/python3.8/site-packages/numpy/core/include -I/Users/barnhark/opt/anaconda3/envs/landlab_dev/include/python3.8 -I/Users/barnhark/opt/anaconda3/envs/landlab_dev/include/python3.8 -c landlab/utils/_matrix.c -o build/temp.macosx-10.9-x86_64-3.8/landlab/utils/_matrix.o
clang: error: no such file or directory: 'landlab/utils/_matrix.c'
clang: error: no input files
error: command 'gcc' failed with exit status 1
make: *** [install] Error 1

@gregtucker @mcflugen

[mcflugen]

@mdpiper In your PR would you please give the entire README a quick read and edit as necessary? For instance, I noticed it says something about Python 3.8 support is coming soon! Also, backslashes instead of slashes for path names?! What?!

[mdpiper]

@mcflugen You betcha. I’ll also scrub landscape.io.