[Bioc-devel] build error on ChemmineOB

My package ChemmineOB 1.33.0 is failing to install or build: 
https://bioconductor.org/checkResults/devel/bioc-LATEST/ChemmineOB/palomino3-install.html???????

The error is:

c:/openbabel/src/x64/include/openbabel/math/align.h:26:10: fatal error: 
Eigen/Core: No such file or directory
 ?? 26 | #include <Eigen/Core>
 ????? |????????? ^~~~~~~~~~~~?


The expected location of the Eigen library is 
-IC:/openbabel3/deps/eigin-3.3.7 . Could you please check that it is 
installed at that location? Or if it should be somewhere else, please 
let me know what the path is. Thank you.

Kevin