> ./configure
configure: loading site script /usr/share/site/x86_64-unknown-linux-gnu
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /usr/bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking whether make supports nested variables... yes
checking for gcc... gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking whether gcc understands -c and -o together... yes
checking for style of include used by make... GNU
checking dependency style of gcc... gcc3
checking for pkg-config... /usr/bin/pkg-config
checking pkg-config is at least version 0.9.0... yes
checking for x11... no
configure: error: Package requirements (x11) were not met:

No package 'x11' found

Information for pattern x11:
----------------------------
Repository      : openSUSE-Leap-15.0-Update
Name            : x11
Version         : 20171206-lp150.15.9.1
Arch            : x86_64
Vendor          : openSUSE
Installed       : Yes
Visible to User : Yes
Summary         : X Window System
Description     :
    The X Window System provides the only standard platform-independent networked graphical window system bridging the heterogeneous platforms in today's enterprise: from network servers to
    desktops, thin clients, laptops, and handhelds, independent of operating system and hardware.