So, I moved the binary that resulted out into AFS-land - and it failed to run. Hrmppphhhh. Changing the AFS owner to someone with a UID on the local box caused the sbcl binary to run. Tried the build again. Failure mode.
Just to prove I wasn't halucinating, I moved it all back to the local disk and rebuilt from scratch - which worked fine again.
The joke here is that the errors were related to malloc()ing memory from the heap - something which should have no relationship whatsoever with the fact that the image is in AFS-land.
Just for gigles, I took some C code I had lying around that did a few malloc()s and compiled and ran it. It didn't seem to make one bit of difference whether or not it was in AFS-land - nor what UID was the owner of the binary.
I'm confused, to say the least.