[Ben Reser] > I've added the needed .ycm_extra_conf.py and a make target to produce > the compilation database in r1476374. So using these plugins with the > Subversion code base should be as simple as installing the plugins > into vim per their directions, installing bear, running make clean && > make compile-commands.
Speaking of 'make clean', compile_commands.json really needs to be in either CLEAN_FILES or EXTRACLEAN_FILES. Also, it sounds like compile_commands.json is dependent on the build configuration, and thus should go into $(abs_builddir), not $(abs_srcdir).

