Re: make check hangs in alpha5

Hitoshi Harada <umi(dot)tanuki(at)gmail(dot)com> wrote:

> Just note, I rebooted the guest VM today and retried but things are as
> before. The host reboot doesn't affect either.

Bad luck. :-(

> I also tried another CentOS5.4 VM on the same VirtualBox and succeeded
> to build. Another RHEL Server 5.2 (Tikanga) x86_64 real machine can
> also build alpha5.

Well, that sounds like a workaround: at least you can continue work,
although it doesn't leave a lot of confidence that you won't have to
reinstall _another_ virtual machine from time to time. :-(

> Seems quite hopeless but it's surely reproducible.

They always are, but it can take a while. Back when I used to work in
kernel support we had one problem take a year. We were Not Pleased, to
put it mildly. (Nor was the main customer seeing it.) We got to the
answer in the end, but oh boy, it was ugly on the way, and not our
finest moment.

(Answer was that someone left 'volatile' off a variable declaration, so
it was a race condition. A race condition that came and went as code
around the incorrect line of code was changed, so only some patch levels
were affected. Plus, like any race condition, customers either tended
never to see it or tended to hit it semi-regularly. It was
... difficult. It was't me who solved it; fortunately qsomeone else
"owned" it and eventually thought to disassemble all the different patch
levels. (He was looking for a compiler bug, unsurprisingly; when the
problem first occurred he had only one patch version to deal with as
well, so that approach didn't suggest itself first off, and everyone
(where "everyone" was quite a lot of people) overlooked the missing
'volatile' during code reviews.)

Back to VirtualBox: it blew up on me _again_ yesterday, refusing to boot
FreeBSD as anything but 32 bit, no matter how I coaxed it and no matter
that it had been running a 64bit installation for weeks before that. As
booting a FreeBSD 64 bit kernel in 32 bit mode doesn't work (surprise!)
I have exorcised VirtualBox from my system (like Parallels before it,
which was even worse), and am deciding today qwhat real hardware I shall
buy to replace VirtualBox. (Before anyone suggests VMware Fusion:
they're honest enough to admit to not supporting one of the operating
systems I care about, so that's not a solution, unfortunately.)

So I can't test with VirtualBox anymore to help out, sorry.

Giles