pxrConfig.cmake generated on Linux not usable between distros due to absolute path of libm.so

[pmolodo]

Description of Issue

On Linux, the generated pxrTargets.cmake will set an absolute path to libm.so inside of arch's INTERFACE_LINK_LIBRARIES.

This means that when compiling a plugin using the pxrConfig.cmake, if the path to libm.so differs from that used on the machine where USD was compiled, a linking error will be generated, because it can't find that exact absolute path.

In practice, this often makes the generated pxrConfig.cmake specific to the Linux distro used to generate it - for instance, if you compile on CentOS 7 (which uses /usr/lib64/libm.so), you can't use that pxrConfig.cmake on Ubuntu 20.04 (/lib/x86_64-linux-gnu/libm.so)

Steps to Reproduce

1. Compile USD on CentOS 7 (or, likely, any CentOS version)
2. Copy the resulting install to an Ubuntu 20.04 machine (or, likely, any Ubuntu version)
3. Try to build a cmake project, using the default Makefile generator, that uses the generated pxrConfig.cmake, and links against pretty much any USD lib (ie, anything that transitively requires the arch lib
4. CMake configuring will work successfully, but you will see an error like this from make when building:

make[2]: *** No rule to make target '/usr/lib64/libm.so', needed by 'my_usd_plugin.so'.  Stop.

System Information (OS, Hardware)

Linux

Package Versions

USD 24.02 (dcbc1ca)

[jesschimein]

Filed as internal issue #USD-8924

[nvmkuruc]

@pmolodo Do you think this issue has been addressed now that #2796 has been merged?

[pmolodo]

Yes - fixed via #2796