Okay doing the correct git clone I fail with the same error as I did with your tree. I am not sure if this is due to a bug in autogen.sh or a feature of the mac autobuild scripts. I am not sure where to report it either.
richard-hydes-macbook-air:dfu-util rich$ ./configure --prefix=/opt/local/ checking for a BSD-compatible install… /usr/bin/install -c
checking whether build environment is sane… yes
checking for a thread-safe mkdir -p… m4/install-sh -c -d
checking for gawk… gawk
checking whether make sets $(MAKE)… yes
checking whether to enable maintainer-specific portions of Makefiles… no
checking for gcc… gcc
checking for C compiler default output file name… a.out
checking whether the C compiler works… yes
checking whether we are cross compiling… no
checking for suffix of executables…
checking for suffix of object files… o
checking whether we are using the GNU C compiler… yes
checking whether gcc accepts -g… yes
checking for gcc option to accept ISO C89… none needed
checking for style of include used by make… GNU
checking dependency style of gcc… gcc3
./configure: line 3332: syntax error near unexpected token USB,' ./configure: line 3332: PKG_CHECK_MODULES(USB, libusb >= 0.1.4,’
richard-hydes-macbook-air:dfu-util rich$
and
*line 3331 in ./configure
Checks for libraries.
PKG_CHECK_MODULES(USB, libusb >= 0.1.4,
{ { echo “$as_me:$LINENO: error: *** Required libusb >= 0.1.4 not installed ***” >&5
echo “$as_me: error: *** Required libusb >= 0.1.4 not installed ***” >&2;}
{ (exit 1); exit 1; }; })