There seem to be two problems: the kernel module nikal fails to build; and once that is fixed, the library libniPythonInterface.so can't be found. I managed to fix the first problem, but am stuck on the second. This seems to be the same problem as this post, no solution given.
First problem: The kernel modules of NI-VISA 19.2 (current version) failed to install on the current version of CentOS 8 (kernel version 4.18.0-193.28.1.el8_2.x86_64). The output from step 3 of the installation procedure, "sudo dkms autoinstall" is attached. The problem is that nikal.ko fails to build because of a type mismatch (log file attached). I fixed this by editing /var/lib/dkms/nikal/19.2.0f0/source/nikal.c, changing the return value of nNIKAL190_vmaPageFaultHandler and nNIKAL220_vmaPageFaultHandlerPageList from "int" to "unsigned int" (lines 368 and 373).
Second problem: After successfully building the kernel modules and rebooting, the "VISA Interactive Control" program (/usr/bin/NIvisaic) fails with the error, "Can't find library libniPythonInterface.so". I haven't been able to find this library.
Does anyone have a solution?
No, I was unable to make any headway beyond what I described. In fact, we only need USB-TMC and VXI11 support, so we're abandoning NI-VISA and writing our own drivers. Given the lack of support on Mac and Linux, and failure to fix known bugs even on Windows, we feel we'll come out ahead in the end.
i encountered a similar issue on RHEL 7 where a LabVIEW application threw the "Can't find library libniPythonInterface.so" error. i had not yet installed the LabVIEW runtime. Installing the runtime resolved the issue.