Problem building Qsynth 0.4.3 FLUIDSYNTH library not found

Also posted to askubuntu http://askubuntu.com/questions/888957/problem-building-qsynth-0-4-3-flui...

I'm trying to build qsynth 0.4.3 from source. I know I need fluidsynth installed and I have done that. But running ./configure in qsynth errors out.

$ ./configure --with-fluidsynth=/usr/local/include/fluidsynth
checking for gcc... gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
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 how to run the C preprocessor... gcc -E
checking for g++... g++
checking whether we are using the GNU C++ compiler... yes
checking whether g++ accepts -g... yes
checking how to run the C++ preprocessor... g++ -E
checking for pkg-config... /usr/bin/pkg-config
checking pkg-config is at least version 0.9.0... yes
checking for g++ major version... 4
checking for qmake-qt5... no
checking for qmake... /usr/lib/x86_64-linux-gnu/qt5/bin//qmake
checking for Qt major version... 5
checking for Qt install path... /usr/lib/x86_64-linux-gnu/qt5/bin
checking for qmake... (cached) /usr/lib/x86_64-linux-gnu/qt5/bin//qmake
checking for Qt install headers... /usr/include/qt5
checking for Qt install libraries... /usr/lib/x86_64-linux-gnu
checking for Qt library version >= 5.1... yes
checking for moc... /usr/lib/x86_64-linux-gnu/qt5/bin/moc
checking for uic... /usr/lib/x86_64-linux-gnu/qt5/bin/uic
checking for lupdate... /usr/bin/lupdate
checking for lrelease... /usr/bin/lrelease
checking for main in -lm... yes
checking for main in -lX11... yes
checking for main in -lXext... yes
checking for lroundf in -lm... yes
checking for FLUIDSYNTH... no
configure: error: *** FLUIDSYNTH library not found.

I've also tried

./configure --with-fluidsynth=/usr/local/lib64
./configure --with-fluidsynth=/usr/local/include/

but same result

I successfully compiled and installed fluidsynth from the master branch

$ sudo make install
[sudo] password for :
[ 97%] Built target libfluidsynth
[100%] Built target fluidsynth
Install the project...
-- Install configuration: "RelWithDebInfo"
-- Installing: /usr/local/lib64/pkgconfig/fluidsynth.pc
-- Installing: /usr/local/bin/fluidsynth
-- Removed runtime path from "/usr/local/bin/fluidsynth"
-- Installing: /usr/local/lib64/libfluidsynth.so.1.5.2
-- Installing: /usr/local/lib64/libfluidsynth.so.1
-- Installing: /usr/local/lib64/libfluidsynth.so
-- Installing: /usr/local/include/fluidsynth.h
-- Installing: /usr/local/include/fluidsynth/audio.h
-- Installing: /usr/local/include/fluidsynth/event.h
-- Installing: /usr/local/include/fluidsynth/gen.h
-- Installing: /usr/local/include/fluidsynth/log.h
-- Installing: /usr/local/include/fluidsynth/midi.h
-- Installing: /usr/local/include/fluidsynth/misc.h
-- Installing: /usr/local/include/fluidsynth/mod.h
-- Installing: /usr/local/include/fluidsynth/ramsfont.h
-- Installing: /usr/local/include/fluidsynth/seq.h
-- Installing: /usr/local/include/fluidsynth/seqbind.h
-- Installing: /usr/local/include/fluidsynth/settings.h
-- Installing: /usr/local/include/fluidsynth/sfont.h
-- Installing: /usr/local/include/fluidsynth/shell.h
-- Installing: /usr/local/include/fluidsynth/synth.h
-- Installing: /usr/local/include/fluidsynth/types.h
-- Installing: /usr/local/include/fluidsynth/voice.h
-- Installing: /usr/local/include/fluidsynth/version.h
-- Installing: /usr/local/share/man/man1/fluidsynth.1

im running Mint 17.3 (ubuntu 14) any pointers appreciated