trying to improve online docs rendering

1 job for master in 1 minute and 19 seconds (queued for 2 seconds)
Name Stage Failure
failed
pages Deploy
      |                          ^~~~~~~~~~~~~~~~~~~~~~~~~~
x86_64-linux-gnu-gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O2 -Wall -g -ffile-prefix-map=/build/python3.9-1n6GrT/python3.9-3.9.5=. -fstack-protector-strong -Wformat -Werror=format-security -g -fwrapv -O2 -g -ffile-prefix-map=/build/python3.9-1n6GrT/python3.9-3.9.5=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fPIC -I/usr/local/lib/python3.9/dist-packages/numpy/core/include -I/usr/include/python3.9 -c tools/projectSphereC3.cython/projectSphereC.cpp -o build/temp.linux-x86_64-3.9/tools/projectSphereC3.cython/projectSphereC.o -I/usr/local/include/eigen3 -I/usr/include/eigen3
tools/projectSphereC3.cython/projectSphereC.cpp:4:10: fatal error: Eigen/Dense: No such file or directory
4 | #include <Eigen/Dense>
| ^~~~~~~~~~~~~
compilation terminated.
error: command '/usr/bin/x86_64-linux-gnu-gcc' failed with exit code 1
Cleaning up file based variables
ERROR: Job failed: exit code 1