opa - error on attempt to make whiteboard

so far so good with opa. I'd like to try playing around with the whiteboard code, but I'm having difficulty getting it to compile on my ec2 instance

I did:

wget https://github.com/hhugo/OpaWhiteBoard/tarball/mas开发者_JAVA技巧ter
tar -xvzf master
cd hhugo-OpaWhiteBoard-004e4f1
make

and then I get:

opa-plugin-builder -I +cairo src/opacairo/cairo.ml -o cairo
make[1]: Entering directory `/home/myhome/src/opa/whiteboard/hhugo-OpaWhiteBoard-004e4f1/cairo.opp'
/usr/lib/opa/ocaml/bin/ocamlopt.opt   -I /usr/lib/opa/static -I +cairo -c cairoMLRuntime.mli
/usr/lib/opa/ocaml/bin/ocamlopt.opt   -I /usr/lib/opa/static -I +cairo -c     cairoMLRuntime.ml
File "src/opacairo/cairo.ml", line 3, characters 22-41:
Error: Unbound module Cairo
make[1]: *** [cairoMLRuntime.cmx] Error 2
make[1]: Leaving directory `/home/myhome/src/opa/whiteboard/hhugo-OpaWhiteBoard-004e4f1/cairo.opp'
Error
building failure due to error(s) in source files

make: *** [cairo.opp] Error 1

I didn't find much by googling the error