Bug#471598: More info
ii libc6 2.7-9
GNU C Library: Shared libraries
ii libc6-i386 2.7-9
GNU C Library: 32bit shared libraries for AM
OK, it looks like all three of the "SBCL is horribly borken" bugs
(471598, 471147, 469015) are caused by a longstanding kernel bug
exposed by gcc-4.3, which libc6 started using as of 2.7-9.
(Coincidentally, this was front page news on slashdot today.)
Discussion of the issue:
Root bug in Debian (I think):
It looks like 2.6.25 will fix this, and we might have a backport to
2.6.24 even (though it's a "critical" bug and the patch was posted
almost 2 weeks ago and there's been no apparent action since).