OpenBTS-UMTS on Ubuntu 18.04, make fails: recipe for target 'CLI.lo' failed

Question

I'm trying to install OpenBTS-UMTS on Ubuntu 18.04. I ran successfully

./autogen.sh

and

./configure

then

make

fails with the following error

Makefile:501: recipe for target 'CLI.lo' failed
make[2]: *** [CLI.lo] Error 1
make[2]: Leaving directory '/home/foo/Downloads/OpenBTS-UMTS/CLI'
Makefile:550: recipe for target 'all-recursive' failed
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory '/home/foo/Downloads/OpenBTS-UMTS'
Makefile:481: recipe for target 'all' failed
make: *** [all] Error 2

How to solve? Thanks to who will try to help.

Same version of OpenBTS-UMTS compiled and installed successfully on Ubuntu 16.04

Answer 1

Ubuntu 18 use g++-7 by default, the problem is related with static const data members may be initialized in the class declaration. This is the problematic declaration:

../UMTS/UMTSRadioModem.h:181:28: error: ‘constexpr’ needed for in-class initialization of static data member ‘const float UMTS::RadioModem::mRACHThreshold’ of non-integral type [-fpermissive] static const float mRACHThreshold = 10.0; ^~~~~~~~~~~~~~

(more information here)

To compile OpenBTS-UMTS in your Ubuntu 18, install g++-5: apt-get install g++-5-multilib and then configure the g++ versions using update-alternatives (see also this post)