Ubuntu 26.03 ParaView compile and run issues

Dear ParaView support

I have moved to an Ubuntu 26.04 laptop with an NVIDIA GPU, and attempting to compile ParaView v6.1. As a reference, I have also downloaded the pre-compiled binary (ParaView-6.1.0-MPI-Linux-Python3.12-x86_64) which I am able to run, in parallel with

./bin/mpiexec -n 2 ./bin/pvserver

__NV_PRIME_RENDER_OFFLOAD=1 __GLX_VENDOR_LIBRARY_NAME=nvidia ./bin/paraview --server=localhost

My own compilation works fine without MPI, but if setting PARAVIEW_USE_MPI=ON, I cannot run anything (paraview standalone, or a combination of pvserver+paraview) because I get stuck opening sockets. Here is a partial output of strace (the first part is successfull), followed by the blocking part

socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0) = 25
connect(25, {sa_family=AF_UNIX, sun_path=@“/tmp/.X11-unix/X0”}, 20) = 0
getpeername(25, {sa_family=AF_UNIX, sun_path=@“/tmp/.X11-unix/X0”}, [124 => 20]) = 0
uname({sysname=“Linux”, nodename=“paradiso”, …}) = 0
access(“/run/user/1001/.mutter-Xwaylandauth.ASGBP3”, R_OK) = 0
openat(AT_FDCWD, “/run/user/1001/.mutter-Xwaylandauth.ASGBP3”, O_RDONLY) = 26

the blocking part here:
close(25) = 0
socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0) = 25
connect(25, {sa_family=AF_UNIX, sun_path=@“/tmp/.X11-unix/X1”}, 20

on this second call to connect, execution gets stuck. My colleagues, more knowledgeable than me about sockets and ssh issues tell me that this is caused by Xwayland issues with opening/listening with multiple processes. Frankly, this is beyond my zone of comfort.

Question to the ParaView developers. Which options would you suggest (for the MPI part, and the rendering part) to get past these issues? Are the compile commands available to see how
ParaView Build ID: superbuild af9bb3207d40b64f97c64a9c319d483ff3b17d03 (!1332)
was built?I am using mpich v4.3.2

TIA

I had the same issue on my ubuntu 26.04 laptop. With USE_MPI=ON, paraview GUI was not starting up. So I switched to USE_MPI=OFF and everything works normally. Sorry, I haven’t done any debugging yet, so I don’t have any logs to share at the moment, but it looks like I saw the same issue. I am commenting here just to follow the thread if someone finds or shares a solution.
I am using an Open MPI v5.0.10

I observed that the ParaView GUI does not start for exactly the same reason I noted above. It gets stuck opening the socket I listed => connect(…@”/tmp/.X11-unix/X1”)