Configure options for faster Jenkins builds

[Stephan Bergmann]

On 13/10/2019 21:15, Luboš Luňák wrote:
>   And --disable-symbols is basically like adding -g0 to CXXFLAGS. Most setups
> build with --enable-dbgutils to build with full debug builds, but in fact
> generating debug symbols mostly seems like a waste for Jenkins builds. Is
> that actually used for something? I know unittests on Linux print backtraces
> on crashes/aborts, but I've just tried adding abort() in a random unittest
> and the backtrace is not very useful, because it doesn't use debug symbols
> anyway. And with just 'make starmath.build' adding 'ENABLE_SYMBOLS_FOR='
> saves again about 10% of build time here.

Was the backtrace printed by gdb inspecting the core file, or was it 
printed from within the implementation of abort(2) in glibc?

For the tests to print gdb-generated backtraces on Linux, core files 
must be enabled (`ulimit -c unlimited`) and be stored as files named 
core* in cwd (see /proc/sys/kernel/core_pattern).  When those conditions 
are not met anyway for the relevant Gerrit/Jenkins builds, 
--enable-symbols likely doesn't give any benefit.