Re: Building Cygwin fails with "newlib-cygwin/winsup/cygwin/math/truncl.c:24:15: error: ‘FE_TOWARDZERO’ undeclared (first use in this function)" ...

[Mark Geisert]

Hi Roland,

On 7/1/2026 9:43 AM, Roland Mainz via Cygwin wrote:
> Hi!
> 
> ----
> 
> Is anyone else seeing this build failure:
> ---- snip ---
> $ uname -a
> CYGWIN_NT-10.0-19045 bloodbath039 3.6.9-1.x86_64 2026-04-21 15:46 UTC
> x86_64 Cygwin
> $ git clone -b cygwin-3_6-branch git://cygwin.com/git/newlib-cygwin.git
> $ cd newlib-cygwin/winsup/
> $ ./autogen.sh
> $ cd ../..
> $ mkdir testinstall && cd testinstall/
> $ /home/roland_mainz/work/cygwin/newlib-cygwin/winsup/configure
> --prefix=/home/roland_mainz/work/cygwin/testinstall
> ...
> $ time nice make
[...]
Looks like you're building in the source directory.  That won't work. 
You need a separate build directory, in which you run the configure from 
the source directory, and then run make in that build directory.  Take a 
look at the FAQ again.  You're almost there :-).

..mark