manipulating FPU rounding modes on alpha
I'm maintaining cgal (non-free), a package for computational geometry
that requires manipulating the FPU rounding mode for some math
operations. I need some help concerning an alpha specific problem.
It turned out that the FPU rounding macros in 3.3-1 didn't work on alpha
(search for ERROR in ). Uwe Schindler kindly allowed me to use his
alpha machine to debug the problem. I found out that the software
contained #ifdef's with specific macros for alpha. These macros didn't
work (I don't know whether they never worked or don't work any longer).
The generic macros from glibc worked.
Based on this I uploaded 3.3-2 using the generic macros from glibc. But
when the package was build on the buildd, the test failed again .
Unfortunately, it went unnoticed.
Now upstream released 3.3.1 also using the generic glibc macros. And
again, the test failed .
I just build the package manually, and the test succeeds!
I have no clue how to debug this problem. The test works if the package
is build manually, but fails on the buildd (ds10). I have no experience
with alpha and don't know how to track this down.
Could someone try to build the package manually and see if it fails?. It
would be helpful to have a machine where the build fails when the
package is build manually.
One difference is that Uwe's machine runs current testing (libc6.1-dev
2.6.1-1), while the buildd uses older versions (libc6.1-dev_2.6-2 for
3.3-2 and libc6.1-dev_2.6-5 for 3.3.1-1) 
Has someone a chroot environment with libc6.1-dev 2.6 (not 2.6.1)? A
build failure in such a environment would indicate that the older glibc
might cause the problem.
Let me know if you need further information.
P.S.: Please CC: me on replies.
Shouldn't buildds build the packages in a current sid chroot?