error with make all / still supported?

[greenwoodms06]

I recently stumbled upon your work and thought I'd give it a go as an alternative to ExternalMedia. Are you still keeping this repo current?

I finally got REFPROP to work on linux with your librefprop.so. Thank you! Couldn't get the REFPROP-cmake of Ian's to work.

However, with the modelica wrapper, I tried to follow your instructions and it failed with make all. Error below

cp  ./src/refprop_wrapper.h ./bin
cp  ./src/refprop_library.h ./bin
g++ -O3 -ffast-math -Wall -pedantic -fbounds-check -ansi -Wpadded -Wpacked -malign-double -mpreferred-stack-boundary=8 -o ./src/refprop_wrapper.o -c src/refprop_wrapper.cpp
src/refprop_wrapper.cpp: In function ‘double props_REFPROP(char*, char*, char*, double*, double*, double*, double, double, double*, int, char*, char*, int, int, int)’:
src/refprop_wrapper.cpp:2137:9: warning: variable ‘val1’ set but not used [-Wunused-but-set-variable]
  double val1 = 0;
         ^
src/refprop_wrapper.cpp:2138:9: warning: variable ‘val2’ set but not used [-Wunused-but-set-variable]
  double val2 = 0;
         ^
src/refprop_wrapper.cpp:2139:9: warning: variable ‘var1’ set but not used [-Wunused-but-set-variable]
  double var1 = 0;
         ^
src/refprop_wrapper.cpp:2140:9: warning: variable ‘var2’ set but not used [-Wunused-but-set-variable]
  double var2 = 0;
         ^
g++ -rdynamic -fPIC -shared -Wl,-soname,librefprop_wrapper.so.0 -O3 -ffast-math -Wall -pedantic -fbounds-check -ansi -Wpadded -Wpacked -malign-double -mpreferred-stack-boundary=8 -o ./bin/librefprop_wrapper.so ./src/refprop_wrapper.o -lrefprop -ldl
/usr/bin/ld: cannot open output file ./bin/librefprop_wrapper.so: Not a directory
collect2: error: ld returned 1 exit status
Makefile:135: recipe for target 'bin/librefprop_wrapper.so' failed
make: *** [bin/librefprop_wrapper.so] Error 1

Thoughts?