Ubuntu
pcl package

PCLConfig.cmake fails to find pcl due to usrmerge

Bug #1896118 reported by Lucas D. Cagle on 2020-09-17

This bug affects 1 person

Affects		Status	Importance	Assigned to	Milestone
	pcl (Ubuntu)	New	Undecided	Unassigned

Bug Description

1) 20.04 LTS
2) 1.10.0+dfsg-5ubuntu1
3) cmake's find_package() finds pcl for project build
4) cmake's find_package() fails to find pcl

On fresh installs of 20.04, /lib is symlinked to /usr/lib by default. This seems to cause problems with the relative paths used at line 401 in PCLConfig.cmake.in to set PCL_ROOT. cmake seems to be searching /lib first for the cmake config files. This causes the relative path used in line 401 to resolve to / instead of the intended /usr, which then cause subsequent lines to fail to find pcl.

For full disclosure, I encountered this while using a Singularity container, but I am largely confident this isn't a container-specific issue.

Revision history for this message

Jochen Sprickerhof (v-launchpad-jochen-sprickerhof-de) wrote on 2020-10-17:

I failed to reproduce this using:
1. Fresh installed 20.4
2. sudo apt install g++ cmake libpcl-dev
3. echo "find_package(PCL)" > CMakeLists.txt
4- cmake .

Can you try it again and maybe post your CMakeCache.txt?

Revision history for this message

Lucas D. Cagle (daftpwner) wrote on 2020-10-19:

CMakeCache.txt Edit (13.9 KiB, text/plain)

At the moment, I don't have a machine I can do a fresh reinstall of 20.04 on, but I can reproduce this in a minimal Singularity container. I can share the container recipe file if that would help.

Running the following (after opening a shell in the container) reproduces the error:
1. echo "find_package(PCL)" > CMakeLists.txt
2- cmake .

I've attached my CMakeCache.txt. Running 'cat CMakeCache.txt | grep PCL' produces the following:

Singularity> cat CMakeCache.txt | grep PCL
//The directory containing a CMake configuration file for PCL.
PCL_DIR:PATH=/lib/x86_64-linux-gnu/cmake/pcl

When I get the chance, I can also try it on a fresh 20.04 install once one of my machines is free.