The problem was that previous versions of ubuntu had bug in "ld", which resulted in long linking time for anything with debug info. That is why we have pre-set "debug minimal".
This remembers me the 'tkb' (task builder) linker on vax system at university... it tooks hours to link. They had also a 'ftb' (fast task builder) but they gave access to it only to few people... don't know why
On my ubuntu the build with debug on is fast enough, indeed.