Blockstack App Fails on npm install ERR! configure error

Question

I am trying to learn how to use blockstack https://docs.blockstack.org/browser/hello-blockstack.html which is a react.js type of application.

When I build the app and run npm install this is the error I receive:

C:\Users\Davidb.TC\Desktop\blockstack\hello-world-tutorial\node_modules\tiny-secp256k1>if not defined npm_config_node_gyp (node "C:\Users\Davidb.TC\AppData\Roaming\npm\node_modules\npm\node_modules\npm-lifecycle\node-gyp-bin\\..\..\node_modules\node-gyp\bin\node-gyp.js" rebuild )  else (node "C:\Users\Davidb.TC\AppData\Roaming\npm\node_modules\npm\node_modules\node-gyp\bin\node-gyp.js" rebuild )
gyp ERR! configure error
gyp ERR! stack Error: Command failed: C:\Python37\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:294:12)
gyp ERR! stack     at ChildProcess.emit (events.js:189:13)
gyp ERR! stack     at maybeClose (internal/child_process.js:970:16)
gyp ERR! stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:259:5)
gyp ERR! System Windows_NT 10.0.16299
gyp ERR! command "C:\\Program Files\\nodejs\\node.exe" "C:\\Users\\Davidb.TC\\AppData\\Roaming\\npm\\node_modules\\npm\\node_modules\\node-gyp\\bin\\node-gyp.js" "rebuild"
gyp ERR! cwd C:\Users\Davidb.TC\Desktop\blockstack\hello-world-tutorial\node_modules\tiny-secp256k1
gyp ERR! node -v v10.15.3
gyp ERR! node-gyp -v v3.8.0
gyp ERR! not ok
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! [email protected] install: `node-gyp rebuild`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the [email protected] 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!     C:\Users\Davidb.TC\AppData\Roaming\npm-cache\_logs\2019-04-11T20_16_40_788Z-debug.log

Does anyone know what I must do to fix this error?

Answer 1

These types of node-gyp errors can be caused when Python 3 is installed on the system and it is expecting Python2.7. The node-gyp contributors claim Python3 support is not perfect at the moment and recommend Python2.7 if you encounter any problems.

It may not be necessary though to change Python versions in your case just yet, since it looks like you are on a Windows machine and it's failing on the node-gyp rebuild step. It's probably worth trying the following command first (make sure you are either in CMD or Powershell in Administrator mode:

npm install -g windows-build-tools

The windows-build-tools package is required for node-gyp to work properly on Windows, as stated here. After this, try running npm install again.

---

Still fails?

If the problem persist or another error related to node-gyp occurs, you might have to install Python2.7 and set npm to use Python2.7

npm config set python /path/to/executable/python2.7

You can read more about possible node-gyp issues and how to resolve them on the node-gyp github page.