lfk0.9 compile failure on Linux Ubuntu 18.04 LTS

[ 78%] Building C object lfk-core/CMakeFiles/lfk-core-lib.dir/src/kernels/kernel24.c.o
/root/lfk/lfk-core/src/kernels/kernel24.c: In function ‘kernel_24_exec’:
/root/lfk/lfk-core/src/kernels/kernel24.c:14:10: warning: unused variable ‘l’ [-Wunused-variable]
     long l, k, m24;
          ^
/root/lfk/lfk-core/src/kernels/kernel24.c:10:14: warning: unused variable ‘inner_loop’ [-Wunused-variable]
     unsigned inner_loop;
              ^~~~~~~~~~
[ 81%] Building C object lfk-core/CMakeFiles/lfk-core-lib.dir/src/kernel_factory.c.o
[ 84%] Building C object lfk-core/CMakeFiles/lfk-core-lib.dir/src/kernel_runner.c.o
[ 87%] Building C object lfk-core/CMakeFiles/lfk-core-lib.dir/src/benchmark.c.o
[ 90%] Building C object lfk-core/CMakeFiles/lfk-core-lib.dir/src/platform/platform_unix.c.o
[ 93%] Linking C static library liblfk-core-lib.a
[ 93%] Built target lfk-core-lib
Scanning dependencies of target benchmark
[ 96%] Building C object CMakeFiles/benchmark.dir/main.c.o
[100%] Linking C executable benchmark
/usr/bin/ld: cannot find -lxml2
collect2: error: ld returned 1 exit status
CMakeFiles/benchmark.dir/build.make:95: recipe for target 'benchmark' failed
make[2]: *** [benchmark] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/benchmark.dir/all' failed
make[1]: *** [CMakeFiles/benchmark.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2
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