# Compiling VTK with X11-xcb on Ubuntu 20
**URL:** https://discourse.vtk.org/t/compiling-vtk-with-x11-xcb-on-ubuntu-20/5518
**Category:** Support
**Created:** [April 8, 2021, 9:43am UTC](https://discourse.vtk.org/t/compiling-vtk-with-x11-xcb-on-ubuntu-20/5518 "2021-04-08T09:43:32Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@nantille](https://discourse.vtk.org/u/nantille)
#### Post date: [April 8, 2021, 9:43am UTC](https://discourse.vtk.org/t/compiling-vtk-with-x11-xcb-on-ubuntu-20/5518/1 "2021-04-08T09:43:32Z")
I cloned a vtk nightly-master repo, created a build folder and ran `ccmake ../vtk`
Now I see that it cannot find X11-xcb related stuff:
```auto
X11_xcb_util_INCLUDE_PATH
X11_xcb_util_LIB
X11_xcb_icccm_INCLUDE_PATH
X11_xcb_icccm_LIB
X11_xcb_xfixes_INCLUDE_PATH
X11_xcb_xfixes_LIB
```
If I go ahead and compile VTK without the proper paths for X11, I can still compile VTK but when I run a Python example that apparently requires X11, VTK segfaults as soon as the window opens. The error is `X connection to NAME broken (explicit kill or server shutdown)` where NAME is a weird set of special chars.
However, I have already installed `libx11-xcb-dev` package on Ubuntu 20. I’ve got also `xorg` and `openbox`. I assume I only need X11 client, not server.
If I understand correctly, in the `INCLUDE_PATH`, I should put folders that have header `.h` files and for `LIB`, the `.so` libs. I did find that the libs are under `/usr/lib/x86_64-linux-gnu` but I’m not sure where are the header files.
Even when I set the `LIB` paths, it doesn’t seem to change anything.
_I assume here that the segfault error is related to not found X11 but I could be wrong._
---
### Author:  [@ben.boeckel](https://discourse.vtk.org/u/ben.boeckel)
#### Post date: [May 15, 2021, 7:36pm UTC](https://discourse.vtk.org/t/compiling-vtk-with-x11-xcb-on-ubuntu-20/5518/2 "2021-05-15T19:36:58Z")
Yes, generally VTK ends up calling `abort()`. I don’t think we need XCB headers though. What is `NAME`?