Gentoo's Bugzilla –
Attachment 613164 Details for
Bug 708926dev-ros/pcl_ros-1.7.0 - In file included from .../work/perception_pcl-1.7.0/pcl_ros/tools/pcd_to_pointcloud.cpp:48: /usr/lib/gcc/x86_64-pc-linux-gnu/9.2.0/include/g++-v9/cstdlib:75:15: fatal error: stdlib.h: No such file or directory