bubblestrap and gnat: is gnat always rebuilt whenever I bubblestrap gcc?

[Christian Joensson]

Is it just me...or?

I get the feeling that if I first bootstrap gcc, then update some
files, then bubblestrap to check again... that gnat and friends get
rebuilt?

I really like bubblestrap, it gets me a shorter time to test a patch
or so. However, if gnat and friends somehow are more sensitively
dependent on source changes... I am hesitant to bootstrap with Ada...

Is there anyone else that can confirm my feeling with some in depth
facts... or am I simply misguided by my feeling?

-- 
Cheers,

/ChJ