Makefile:1: /env.mak: No such file or directory

I'm trying to run a node application on my Synology box that depends on ursa. Installing the dependencies with npm install fails while trying to gyp build ursa; the output is paste below. I know very little about make, does this error mean something to someone? The first line of the Makefile in node_modules/ursa/build/ includes /env.mak.

Thanks

> ursa@0.9.1 install /home/proj/node_modules/ursa
> node-gyp rebuild

make: Entering directory `/home/proj/node_modules/ursa/build'
Makefile:1: /env.mak: No such file or directory
make: *** No rule to make target `/env.mak'.  Stop.
make: Leaving directory `/home/proj/node_modules/ursa/build'
gyp ERR! build error 
gyp ERR! stack Error: `make` failed with exit code: 2
gyp ERR! stack     at ChildProcess.onExit (/volume1/@appstore/Node.js/usr/lib/node_modules/npm/node_modules/node-gyp/lib/build.js:269:23)
gyp ERR! stack     at ChildProcess.emit (events.js:110:17)
gyp ERR! stack     at Process.ChildProcess._handle.onexit (child_process.js:1074:12)
gyp ERR! System Linux 3.2.40
gyp ERR! command "node"  "/volume1/@appstore/Node.js/usr/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "rebuild"
gyp ERR! cwd /home/proj/node_modules/ursa
gyp ERR! node -v v0.12.4
gyp ERR! node-gyp -v v1.0.3
gyp ERR! not ok 

npm ERR! Linux 3.2.40
npm ERR! argv "/usr/bin/node" "/usr/bin/npm" "install"
npm ERR! node v0.12.4
npm ERR! npm  v2.10.1
npm ERR! code ELIFECYCLE
npm ERR! ursa@0.9.1 install: `node-gyp rebuild`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the ursa@0.9.1 install script 'node-gyp rebuild'.
npm ERR! This is most likely a problem with the ursa package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     node-gyp rebuild
npm ERR! You can get their info via:
npm ERR!     npm owner ls ursa
npm ERR! There is likely additional logging output above.

JoshKaufman / ursa

Makefile:1: /env.mak: No such file or directory #125