[node.js] Node.js: Python not found exception due to node-sass and node-gyp

Suddenly in one of my jenkins environment build has started failing, while in local machine it seems to be working fine as i have python installed,

From the logs i was able to detect that the problem is with internal dependency that is node-gyp v3.5.0 from node-sass v3.8.0 when i researched by visiting this about node-gyp and found the prerequisite that Python needs to be installed.

So my question is that what version of node-sass can i install to bypass this or is there a better solution as my build was running fine till this morning on the same environment.

Node v5.10.1

ERROR LOG

gyp verb check python checking for Python executable "python2" in the PATH
gyp verb `which` failed Error: not found: python2
gyp verb `which` failed     at getNotFoundError (C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\which\which.js:13:12)
gyp verb `which` failed     at F (C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\which\which.js:68:19)
gyp verb `which` failed     at E (C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\which\which.js:80:29)
gyp verb `which` failed     at C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\which\which.js:89:16
gyp verb `which` failed     at C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\isexe\index.js:44:5
gyp verb `which` failed     at C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\isexe\windows.js:29:5
gyp verb `which` failed     at FSReqWrap.oncomplete (fs.js:82:15)
gyp verb `which` failed  python2 { [Error: not found: python2] code: 'ENOENT' }
gyp verb check python checking for Python executable "python" in the PATH
gyp verb `which` failed Error: not found: python
gyp verb `which` failed     at getNotFoundError (C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\which\which.js:13:12)
gyp verb `which` failed     at F (C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\which\which.js:68:19)
gyp verb `which` failed     at E (C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\which\which.js:80:29)
gyp verb `which` failed     at C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\which\which.js:89:16
gyp verb `which` failed     at C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\isexe\index.js:44:5
gyp verb `which` failed     at C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\isexe\windows.js:29:5
gyp verb `which` failed     at FSReqWrap.oncomplete (fs.js:82:15)
gyp verb `which` failed  python { [Error: not found: python] code: 'ENOENT' }
gyp verb could not find "python". checking python launcher 
gyp verb could not find "python". guessing location 
gyp verb ensuring that file exists: C:\Python27\python.exe
gyp ERR! configure error 
gyp ERR! stack Error: Can't find Python executable "python", you can set the PYTHON env variable.
gyp ERR! stack     at Object.failNoPython (C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\node-gyp\lib\configure.js:454:19)
gyp ERR! stack     at Object.<anonymous> (C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\node-gyp\lib\configure.js:480:16)
gyp ERR! stack     at C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\graceful-fs\polyfills.js:284:29
gyp ERR! stack     at FSReqWrap.oncomplete (fs.js:82:15)
gyp ERR! System Windows_NT 6.3.9600
gyp ERR! command "C:\\Program Files\\nodejs\\node.exe" "C:\\Program Files (x86)\\Jenkins\\jobs\\NdbSite-hot-fix-Manual-PreBuild\\workspace\\src\\NdbSite.UI\\node_modules\\node-gyp\\bin\\node-gyp.js" "rebuild" "--verbose" "--libsass_ext=" "--libsass_cflags=" "--libsass_ldflags=" "--libsass_library="
gyp ERR! cwd C:\Program Files (x86)\Jenkins\jobs\NdbSite-hot-fix-Manual-PreBuild\workspace\src\NdbSite.UI\node_modules\node-sass
gyp ERR! node -v v5.10.1
gyp ERR! node-gyp -v v3.5.0
gyp ERR! not ok 
Build failed

Any thoughts are much appreciated, Thanks.

This is 2 years old, but none of them helped me.

I uninstalled my NodeJS v12.8.1 (Current) and installed a brand new v10.16.3 (LTS) and my ng build --prod worked.

I had node 15.x.x , and "node-sass": "^4.11.0". I saw in the release notes from node-sass and saw the node higest version compatible with node-sass 4.11.0 was 11, so I uninstalled node and reinstall 11.15.0 version (I'm working with Windows). Check node-sass releases. (this is what you should see in the node-sass releases.)

Hope that helps and sorry for my english :)

My machine is Windows 10, I've faced similar problems while tried to compile SASS using node-sass package. My node version is v10.16.3 and npm version is 6.9.0

The way that I resolved the problem:

1. At first delete package-lock.json file and node_modules/ folder.
2. Open Windows PowerShell as Administrator.
3. Run the command npm i -g node-sass.
4. After that, go to the project folder and run npm install
5. And finally, run the SASS compiling script, in my case, it is npm run build:css

And it works!!

I had to:

Delete node_modules
Uninstall/reinstall node
npm install [email protected]

worked fine after forcing it to the right sass version, according to the version said to be working with the right node.

NodeJS  Minimum node-sass version   Node Module
Node 12 4.12+   72
Node 11 4.10+   67
Node 10 4.9+    64
Node 8  4.5.3+  57

There was lots of other errors that seemed to be caused by the wrong sass version defined.

so this happened to me on windows recently. I fix it by following the following steps using a PowerShell with admin privileges:

1. delete node_modulesfolder
2. running npm install --global windows-build-tools
3. reinstalling node modules or node-sass with npm install

node-gyp requires old Python 2 - link

If you don't have it installed - check other answers about installing windows-build-tools.

If you are like me and have both old and new Python versions installed, chances are that node-gyp tries to use Python 3. And that results in the following SyntaxError: invalid syntax error.

I found an article about having two Python versions installed. And they recommend renaming Python 2.* executable to python2.exe - link.

So it looks like node-gyp is expecting to find old Python 2 executable renamed. Hence the error message:

...
gyp verb check python checking for Python executable "python2" in the PATH
gyp verb `which` failed Error: not found: python2
...

Once I renamed C:\Python27\python.exe to C:\Python27\python2.exe it worked without errors.

Of course, both C:\Python27\ and C:\Python39\ have to be in PATH variable. And no need in setting old Python version in npm config. Your default Python still will be the new one.

The error message means that it cannot locate your python executable or binary.

In many cases, it's installed at c:\python27. if it's not installed yet, you can install it with npm install --global windows-build-tools, which will only work if it hasn't been installed yet.

Adding it to the environment variables does not always work. A better alternative, is to just set it in the npm config.

npm config set python c:\python27\python.exe

After looking at all the answers, i notice this solution might be very helpful. It explains how to configure "npm" to find your installed python version while installing node-sass. Remember, node-sass requires node-gyp (an npm build-tool) which looks for your python path. Or just install python, and follow the same solution given (in the link). Thanks.

had the same issue lost hours trying to install different version of python on my PC. Simply Upgrade node to the latest version v8.11.2 and npm 5.6.0, then after install [email protected] and you'll be fine.

My answer might not apply to everyone. Node version: v10.16.0 NPM: 6.9.0

I was having a lot of trouble using node-sass and node-sass-middleware. They are interesting packages because they are widely used (millions of downloads weekly), but their githubs show a limited dependencies and coverage. I was updating an older platform I'd been working on.

What I ended up having to do was:

1) Manually Delete node_modules

2) Manually Delete package-lock.json

3) sudo npm install node-sass --unsafe-perm=true --allow-root

4) sudo npm install node-sass-middleware --unsafe-perm=true --allow-root

I had the following help, thanks!

Pre-built binaries not found for [email protected] and [email protected]

Error: EACCES: permission denied when trying to install ESLint using npm

I found the same issue with Node 12.19.0 and yarn 1.22.5 on Windows 10. I fixed the problem by installing latest stable python 64-bit with adding the path to Environment Variables during python installation. After python installation, I restarted my machine for env vars.

Hey I got this error resolved by following the steps

• first I uninstalled python 3.8.6 (latest version)
• then I installed python 2.7.1 (any Python 2 version will work, but not much older and this is recommended)
• then I added c:\python27 to environment variables
• my OS is windows, so I followed this link
• It worked