Failure to regenerate IP if no graphical output is available

I have an automated CI pipeline that checks out sources, regenerates IP blocks, compiles the sources and generates a bitstream. Quartus is invoked like this:

#! /bin/sh -e
mw-regenerate pcie_reconfig.vhd
mw-regenerate pcie_serdes.vhd
mw-regenerate pcie.vhd
mw-regenerate pll.vhd
# patch frequency of fixedclk_serdes
sed -i -e '/fixedclk_serdes/s/100/125/' pcie.sdc
quartus_map pcie_test
quartus_fit pcie_test
quartus_asm pcie_test
quartus_sta pcie_test
quartus_eda pcie_test

This works fine when run on a workstation, but fails when run on the CI server, because the mw-regenerate command requires an X server connection, even if it doesn't open a window.

I can work around this by using an Xvfb instance, but I wonder if there is a better way to regenerate the IP blocks from a scripted build, so I can drop this requirement.