I can confirm that the jvcustomlazr package cannot be compiled on Ubuntu 20.10 (I don't have a XUbuntu 22.04 available at the moment).
When you load this package via "Package" > "Open package file" and try to compile it, compilation will stop in unit JvThumbnails, procedure TJvThumbnail.GetFileInfo, line "FDFilesize := info.size". Obviously the "size" element is not found. CTRL-clicking on "info" brings me to the declaration "info: stat", and CTRL-clicking on "stat" again brings me to the declaration of the Stat record. In this record all elements have a prefix "st_". Therefore I tried to change the faulty line to "FDFileSize := info.st_size" - and now the package was compiling. The designtime package, jvcustomlazd, was compiling, too, and the Outlookbar sample project is running - problem solved.
I don't know how this issue crept in, maybe a left-over from the original Delphi/Kylix version? I'll do some more tests on other Linux compilations for which I have a VM, and if they show the same issue, I'll commit this change to the CCR repository.