currently, compilation of LyX2.3.1-1 fails on Ubuntu 18.04.1 LTS.
This is the complete output of ./configure:
root@dell:/local/lyx# ./configure
configuring LyX version 2.3.0
checking for build type... release
checking for version suffix...
checking whether Qt5 is requested... no
checking build system type... x86_64-pc-linux-gnu
checking host system type... x86_64-pc-linux-gnu
checking target system type... x86_64-pc-linux-gnu
checking what packaging should be used... posix
checking whether to enable maintainer-specific portions of Makefiles... no
checking whether make supports nested variables... yes
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... configure: error: unsafe
absolute working directory name
