bison 2.4.1 configure fails during forced update on 10.6.1 ("cannot find output from flex")

[etiffany@…]

After following the wiki instructions for updating ("migrating") to a new OS, attempting

sudo port -f uninstall installed and \( gawk grep gsed perl5 perl5.8 perl5.10 \)

and then

sudo port upgrade --force installed

progress stopped while running configure for bison. Performing

sudo port -v upgrade --force bison

produces a lot of output ending with this:

---> Configuring bison checking for a BSD-compatible install... /usr/bin/install -c checking whether build environment is sane... yes checking for a thread-safe mkdir -p... build-aux/install-sh -c -d checking for gawk... gawk checking whether make sets $(MAKE)... yes checking for style of include used by make... GNU checking for gcc... /usr/bin/gcc-4.2 checking for C compiler default output file name... a.out checking whether the C compiler works... yes checking whether we are cross compiling... no checking for suffix of executables... checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether /usr/bin/gcc-4.2 accepts -g... yes checking for /usr/bin/gcc-4.2 option to accept ISO C89... none needed checking dependency style of /usr/bin/gcc-4.2... gcc3 checking for /usr/bin/gcc-4.2 option to accept ISO C99... -std=gnu99 checking for /usr/bin/gcc-4.2 -std=gnu99 option to accept ISO Standard C... (cached) -std=gnu99 checking for ranlib... ranlib checking whether /usr/bin/gcc-4.2 -std=gnu99 and cc understand -c and -o together... yes checking how to run the C preprocessor... /usr/bin/gcc-4.2 -std=gnu99 -E checking for grep that handles long lines and -e... /usr/bin/grep checking for egrep... /usr/bin/grep -E checking for ANSI C header files... yes checking for sys/types.h... yes checking for sys/stat.h... yes checking for stdlib.h... yes checking for string.h... yes checking for memory.h... yes checking for strings.h... yes checking for inttypes.h... yes checking for stdint.h... yes checking for unistd.h... yes checking minix/config.h usability... no checking minix/config.h presence... no checking for minix/config.h... no checking whether it is safe to define EXTENSIONS... yes checking for flex... flex checking lex output file root... configure: error: cannot find output from flex; giving up Error: Target org.macports.configure returned: configure failure: shell command " cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_devel_bison/work/bison-2.4.1" && ./configure --prefix=/opt/local --infodir=/opt/local/share/info --mandir=/opt/local/share/man --disable-yacc " returned error 1 Command output: checking whether we are cross compiling... no checking for suffix of executables... checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether /usr/bin/gcc-4.2 accepts -g... yes checking for /usr/bin/gcc-4.2 option to accept ISO C89... none needed checking dependency style of /usr/bin/gcc-4.2... gcc3 checking for /usr/bin/gcc-4.2 option to accept ISO C99... -std=gnu99 checking for /usr/bin/gcc-4.2 -std=gnu99 option to accept ISO Standard C... (cached) -std=gnu99 checking for ranlib... ranlib checking whether /usr/bin/gcc-4.2 -std=gnu99 and cc understand -c and -o together... yes checking how to run the C preprocessor... /usr/bin/gcc-4.2 -std=gnu99 -E checking for grep that handles long lines and -e... /usr/bin/grep checking for egrep... /usr/bin/grep -E checking for ANSI C header files... yes checking for sys/types.h... yes checking for sys/stat.h... yes checking for stdlib.h... yes checking for string.h... yes checking for memory.h... yes checking for strings.h... yes checking for inttypes.h... yes checking for stdint.h... yes checking for unistd.h... yes checking minix/config.h usability... no checking minix/config.h presence... no checking for minix/config.h... no checking whether it is safe to define EXTENSIONS... yes checking for flex... flex checking lex output file root... configure: error: cannot find output from flex; giving up

Warning: the following items did not execute (for bison): org.macports.destroot org.macports.configure org.macports.build Error: Unable to upgrade port: 1