The package not installed.

If hpp-core has been installed more recently than this documentation, you need to configure and install again this documentation.

Otherwise, if hpp-core is not installed, you can install using one of the following steps:

get the source code through git:
git clone git+https://github.com:humanoid-path-planner/hpp-core
Then configure, compile and install the package.

Note that you will need to configure and install again this documentation to activate the link to hpp-core.