[tlbuild] dvibook failure on Cygwin

[Ken Brown]

I just did a test build of the trunk (rev 25482) on Cygwin.  The build 
went smoothly, but the dvibook test failed with a segfault:

make[4]: Entering directory 
`/home/kbrown/src/texlive/Build/test/Work/texk/seetexk'
dviselect tests OK
../../../texk/seetexk/seetexk.test: line 23:  8492 Segmentation fault 
    (core dumped) ./dvibook -s4 playsel.dvi playbook.dvi 2> playbook.2
FAIL: seetexk.test

This may well be a Cygwin problem.  But before digging further, I'd like 
to know whether anyone is seeing problems on other platforms.

Thanks.

Ken