Apologies for taking so long to reply. Thank you for the advice on doing
bug reports.
It is not your duty to check whether a bug is fixed in the newest
source code, not for Autoconf and certainly not for GCC. Building
GCC from source code takes 4-8 hours of CPU time if you have the
right recipe for doing that, and it probably takes 3-4 attempts
until you got a working recipe.
My experience of building GCC was that it surprisingly easy, in that I
just followed the instructions and it worked, and by my memory, it
compiled fairly quickly, like in 2 hours or so (multi-threaded) definitely
faster than clang was. Though perhaps this is because the instructions
made it more obvious how to only compile the front ends I cared about or
something.
I ended up eventually writing an ugly hack for GCC to route around a bug
which bothering me (I have not attempted to upstream it yet), so I was
closer to wishing to be an expert there.
