gauche-c-wrapper version 0.6.1-4 failed to build in oneiric

gauche-c-wrapper version 0.6.1-4 failed to build in oneiric
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110816/+build/2693619

Details about the rebuild:
http://people.ubuntuwire.org/~wgrant/rebuild-ftbfs-test/test-rebuild-20110816-oneiric.html

Direct link to the build log: https://launchpad.net/ubuntu/+archive/test-rebuild-20110816/+build/2693619/+files/buildlog_ubuntu-oneiric-amd64.gauche-c-wrapper_0.6.1-4_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 362 lines into the build log:

  0 (run (string-append "" (x->string (or ld CC)) " " (x->string (or l ...
        At line 110 of "/usr/share/gauche-0.9/0.9.1/lib/gauche/package/compile.scm"
  1 args

  2 (with-error-handler (lambda (e) (let ((e e)) (%guard-rec e e (else ...
        [unknown location]
  3 (usage)
        At line 93 of "/usr/bin/gauche-package"
make[2]: *** [c-ffi.so] Error 70
make[2]: Leaving directory `/build/buildd/gauche-c-wrapper-0.6.1/src'
make[1]: *** [all] Error 2
make[1]: Leaving directory `/build/buildd/gauche-c-wrapper-0.6.1'
dh_auto_build: make -j1 returned exit code 2
make: *** [build] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2
******************************************************************************
Build finished at 20110820-1506
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/gauche-c-wrapper-0.6.1