Also since Debian's libopagent.so doesn't link against bfd it fails to be found:

configure:28860: gcc -o conftest -g -O2 conftest.c -lopagent -lpthread -lffi -ldl -lm -L/usr/lib/oprofile -Wl,-rpath,/usr/lib/oprofile

&5
/usr/lib/oprofile/libopagent.so: undefined reference to bfd_check_format' /usr/lib/oprofile/libopagent.so: undefined reference to bfd_init'
/usr/lib/oprofile/libopagent.so: undefined reference to bfd_openr' /usr/lib/oprofile/libopagent.so: undefined reference to bfd_perror'
/usr/lib/oprofile/libopagent.so: undefined reference to bfd_get_mach' /usr/lib/oprofile/libopagent.so: undefined reference to bfd_get_arch'

If I configure --with-oprofile I get an error that libopagent needs to be around.

Here is relevant part from /usr/lib/oprofile/libopagent.la:

Libraries that this one depends upon.

dependency_libs=' -liberty -ldl'

And dependencies:
ldd /usr/lib/oprofile/libopagent.so
linux-vdso.so.1 => (0x00007fff00767000)
libdl.so.2 => /lib/libdl.so.2 (0x00007f83f4a9f000)
libc.so.6 => /lib/libc.so.6 (0x00007f83f474e000)
/lib64/ld-linux-x86-64.so.2 (0x0000003410e00000)

Possible fix for the oprofile part of this bug
This patch makes --without-oprofile work, makes that the default instead of searching for oprofile, and tries to work around http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=537744 by searching for libbfd after pulling in libopagent. Edwin, could you check that this fixes things on your system?

Fix for oprofile part, now checking bfd in the right order
Here's a new patch for testing.

I've committed the OProfile part in r83503. Edwin, do you want to get the ffi part?

anyone willing to finish this off?

Patch to make --disable-libffi work and adjust the default
Here's a patch that makes --disable-libffi work. It also changes the default to not using libffi to match libopagent. I remember Duncan wanting that change, but Nick suggests defaulting to "'on if detected'. that's pretty standard for most software". So I'm waiting for them to agree before committing.

Yeah, that's fine. Go ahead and commit.

Fixed in r95712. I'm happy to change the defaults to pay attention to what's installed if Nick convinces people that's the right behavior.