Solution
https://github.com/gopherjs/gopherjs/blob/master/doc/syscalls.md

cd $GOPATH/src/github.com/gopherjs/gopherjs/node-syscall/
npm install --global node-gyp
node-gyp rebuild
mkdir -p ~/.node_libraries/
cp build/Release/syscall.node ~/.node_libraries/syscall.node

Maybe gopherjs test should warn about node-syscall not being installed?

Maybe gopherjs test should warn about node-syscall not being installed?

It seems gopherjs test requires the syscall module, even though it didn't require it some time ago. I think this is the same issue as #626, so I'll close this as duplicate.

There's also a chance that #710 will fix it, it needs to be finished reviewing.

Otherwise, yes, this should be documented and/or gopherjs test can print a warning/error message if the syscall module is unavoidably needed yet missing.