Installation fails with Python 3

I run the following: npm install msgpack

and get:

> msgpack@1.0.2 install {path}\node_modules\msgpack
> node-gyp rebuild

{path}\node_modules\msgpack>if not defined npm_config_node_gyp (node "C:\Program Files\nodejs\node_modules\npm\node_modules\npm-lifecycle\node-gyp-bin\\..\..\node_modules\node-gyp\bin\node-gyp.js" rebuild )  else (node "C:\Program Files\nodejs\node_modules\npm\node_modules\node-gyp\bin\node-gyp.js" rebuild )
gyp ERR! configure error
gyp ERR! stack Error: Command failed: C:\Path\To\Python\Python36\python.EXE -c import sys; print "%s.%s.%s" % sys.version_info[:3];
gyp ERR! stack   File "<string>", line 1
gyp ERR! stack     import sys; print "%s.%s.%s" % sys.version_info[:3];
gyp ERR! stack                                ^
gyp ERR! stack SyntaxError: invalid syntax
gyp ERR! stack
gyp ERR! stack     at ChildProcess.exithandler (child_process.js:276:12)
gyp ERR! stack     at emitTwo (events.js:126:13)
gyp ERR! stack     at ChildProcess.emit (events.js:214:7)
gyp ERR! stack     at maybeClose (internal/child_process.js:915:16)
gyp ERR! stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:209:5)
gyp ERR! System Windows_NT 10.0.17134
gyp ERR! command "C:\\Program Files\\nodejs\\node.exe" "C:\\Program Files\\nodejs\\node_modules\\npm\\node_modules\\node-gyp\\bin\\node-gyp.js" "rebuild"
gyp ERR! cwd {path}\node_modules\msgpack
gyp ERR! node -v v8.12.0
gyp ERR! node-gyp -v v3.8.0
gyp ERR! not ok
npm WARN photo-manager-fileserver No repository field.
npm WARN photo-manager-fileserver No license field.

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! msgpack@1.0.2 install: `node-gyp rebuild`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the msgpack@1.0.2 install script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     {APPDATA}\npm-cache\_logs\2018-11-10T15_28_49_571Z-debug.log

Because I have Python 3.6 in my PATH, it attempts to use that to run a command which is designed for Python 2, so it fails to install.

I then ran the following:

set PATH=C:\Python27;C:\Program Files\nodejs
npm install --save msgpack

...and the installation worked fine. However, this step shouldn't be necessary, and I wouldn't have thought that having Python 3 in the PATH was such an unusual circumstance.

I don't know enough about NPM packaging to understand where the problem is (or how it might be fixed) but this seemed like the best place to post this issue.

I'm bumping this because I this issue just consumed ~10 hours for me to debug.

This build operates under the assumption that the the shell command python ( whether by alias, symlink, or binary ) will invoke a Python 2.x interpreter.

There seems to be no attempt whatsoever by the build to "see if this system's python command is associated with v1, v2, or v3"; nor does it prompt the user in any sane manner when one could not be found - instead we get an incredibly unhelpful runtime crash from node-gyp indicating something to the effect of "file not found", or whatever Python v2/v3 syntax error happens to crop up first.

I am happy to make a PR to perform a rudimentary check for dependencies if someone would be kind enough to point me in the appropriate area of the code-base to dig into. I'm going to wager the node-gyp stuff might be the real culprit, but something like a "pre-build hook" would be an appropriate opportunity to run this type of audit.

msgpack / msgpack-node

Installation fails with Python 3 #46