Mine

matt@xps ~/src/tanarux $ make clean && time make -j | grep -i warn
Making clean in src
make[1]: Entering directory `/home/matt/src/tanarux/src'
 rm -f tanarux
rm -rf .libs _libs
rm -f *.o
rm -f *.lo
make[1]: Leaving directory `/home/matt/src/tanarux/src'
Making clean in .
make[1]: Entering directory `/home/matt/src/tanarux'
rm -rf .libs _libs
rm -f *.lo
make[1]: Leaving directory `/home/matt/src/tanarux'

real	0m1.245s
user	0m1.863s
sys	0m0.285s