How to quickly test changes in Newlib without rebuilding the whole toolchain

["R. Diez via newlib" <newlib at sourceware dot org>]

Hi all:

I am using Newlib in an embedded environment. This is the makefile I am 
using to build a GCC toolchain with it:

  https://github.com/rdiez/JtagDue/tree/master/Toolchain

I would like to modify Newlib and be able to test the changes quickly. 
One possible use case would be to develop Newlib patches to post to this 
mailing list.

The trouble is, I need to rebuild the whole GCC toolchain if I modify 
Newlib, and that takes a long time.

Is there a way that I can use a different Newlib than the one built into 
the current toolchain?

In order to test the changes, I could run the new version of Newlib on 
my Linux PC, instead of on my embedded target. Maybe under some fast 
emulator for a different architecture, if necessary.

Thanks in advance,
  rdiez