I wouldn't go for debug build by default since you can simply add the debug compile options to the cmake command you use:

$ cmake -D CMAKE_C_FLAGS="-g -ggdb3" -B build -G Ninja
$ ninja -C build

or with make:

$ cmake -D CMAKE_C_FLAGS="-g -ggdb3" -B build
$ cd build
$ make

I think it's totally appropriate to build with debug symbols by default. Note, this is not a "debug build" in the sense of optimization.

If you folks decide to create some kind of minimal package (e.g. a .deb file) you can just run strip.

I tend to agree that debug symbols by default can be useful especially to get some better bug reports ;-)

@os12 sure, you're right about optimization. Actually, in the previous build system (autotools based), I implemented 2 distinct options: --enable-debug and --disable-optimization.
It was not ported to the new cmake based setup yet.
We could set -g by default, and add an option to enable more debug facilities (-ggdb3 & -DDEBUG) and, another one, to disable optimization (-O0).

Following #91 it should be ok. Feel free to reopen another PR if required. Thank you again for the proposal and helping for the discussions.