Hello,

ro2/cross_compile is failing because the linker can't find these packages. find_package() finds them when building natively but using ld's --sysroot option with a ros2 install location outside the sysroot prevents them from being found. This also stops any workarounds with options like rpath, since the sysroot path gets prefixed to any rpath specified.

By adding the packages as dependencies, find_package doesn't need to search the filesystem, fixing the problem.

See also rmw_fastrtps/pull/294

thanks for the patch. Also is this related to #113? @esteve Does this solve your problem here as well?

@Karsten1987 I haven't tried this PR yet, but with ros/pluginlib#154 and #113 I was able to cross compile rosbag2 for aarch64.

However, the changes in this PR are a bit too invasive IMHO, exporting only pluginlib was enough to support crosscompiling, not class_loader. Also, ament_index_cpp shouldn't be exported at all, since it's part of the build phase in this package, not for downstream packages.

Swapping this patch for #113 fixed the problem for me. IMO we should abandon this and go with @esteve 's

Thanks!

With #113 merged, I am going ahead and close this. Feel free to re-open if you concerns were not addressed.