Turns out that bootstrap.sh and, called by that, automake both ignore warning problems and exit fails.
Index: ChangeLog 2006-10-11 Andrew Cagney <cagney@redhat.com> * bootstrap.sh: Pass -Werror to automake. Abort if a sub-directory fails to configure. Index: frysk-core/ChangeLog 2006-10-11 Andrew Cagney <cagney@redhat.com> * bootstrap.sh: Pass -Werror to automake. Index: frysk-gtk/ChangeLog 2006-10-11 Andrew Cagney <cagney@redhat.com> * bootstrap.sh: Pass -Werror to automake. Index: frysk-gui/ChangeLog 2006-10-11 Andrew Cagney <cagney@redhat.com> * bootstrap.sh: Pass -Werror to automake. Index: frysk-imports/ChangeLog 2006-10-11 Andrew Cagney <cagney@redhat.com> * bootstrap.sh: Pass -Werror to automake. Index: frysk-sys/ChangeLog 2006-10-11 Andrew Cagney <cagney@redhat.com> * bootstrap.sh: Pass -Werror to automake.