segfault in 3.10.0

[Andres Varon <avaron@gmail.com>]

Hello Everyone,

Has anyone observed sudden segfaults in OCaml 3.10.0 amd-64 under  
linux? I have this program that has been run for quite a while  
without any segfault (almost a year). It may run for weeks at a time  
in parallel in our cluster, using as many as 256 processors at a  
time. We delayed updating to 3.10.0 due to the changes in camlp4, but  
the day before yesterday I worked on it, upgraded, and suddenly a lot  
of the nightly unit tests in 64 bits fail with a segfault (a LOT of  
them), when every test passed clean with 3.09.3. None of the tests  
for other architectures fail though (windows, mac os X intel and 32- 
bit ppc). One down side is that we have C structures wrapped, so one  
may blame our program.

However, efence and valgrind show no sign of problem, and the fact  
that we have been using those structures for a while, and many test  
iterations have passed for many inputs, and not only us, but many  
people in other computers have compiled and run our program without  
having segfaults ... I'm doubtful.

Unfortunately I have been unable to compile 3.10.0 for 64 bits in our  
g5 under Mac OS X, so that architecture remains untested. The  
segfault is occurring within the OCaml code. Any pointer would be  
greatly appreciated, or suggestions of tools that could help us  
hunting this down ... I'm awfully clueless about what to do today ...  
and it's been just a couple of days :-(

best,

Andres