gyp can't find Python, despite Python running when you type "python"

[Pomax]

I'm trying to install windows-registry on Windows 10 with Node 8.2.1 and NPM 5.3.0, and when the ref dependency is hit, node-gyp kicks in. However, it seems to fail when it tries to run python, despite the fact that python has a PATH entry and will run perfectly fine both when just executing "python" on the command line, or when exec/spawning a command called "python".

The error log is as follows:

c:\Users\Mike\Documents\git\temp\pluginboutique>npm install windows-registry

> ref@1.3.4 install c:\Users\Mike\Documents\git\temp\pluginboutique\node_modules\ref
> node-gyp rebuild


c:\Users\Mike\Documents\git\temp\pluginboutique\node_modules\ref>if not defined npm_config_node_gyp (node "C:\Program Files\nodejs\node_modules\npm\bin\node-gyp-bin\\..\..\node_modules\node-gyp\bin\node-gyp.js" rebuild )  else (node "" rebuild )
gyp ERR! configure error
gyp ERR! stack Error: Can't find Python executable "C:\Program Files\Python35\python.EXE", you can set the PYTHON env variable.
gyp ERR! stack     at PythonFinder.failNoPython (C:\Program Files\nodejs\node_modules\npm\node_modules\node-gyp\lib\configure.js:483:19)
gyp ERR! stack     at PythonFinder.<anonymous> (C:\Program Files\nodejs\node_modules\npm\node_modules\node-gyp\lib\configure.js:508:16)
gyp ERR! stack     at C:\Program Files\nodejs\node_modules\npm\node_modules\graceful-fs\polyfills.js:284:29
gyp ERR! stack     at FSReqWrap.oncomplete (fs.js:152:21)
gyp ERR! System Windows_NT 10.0.15063
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 c:\Users\Mike\Documents\git\temp\pluginboutique\node_modules\ref
gyp ERR! node -v v8.2.1
gyp ERR! node-gyp -v v3.6.2
gyp ERR! not ok
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.1.2 (node_modules\fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.1.2: wanted {"os":"darwin","arch":"any"} (current: {"os":"win32","arch":"x64"})

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! ref@1.3.4 install: `node-gyp rebuild`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the ref@1.3.4 install script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

I don't understand why there would be any reason to be looking for Python in the indicated locations when there is already a PATH binding that makes python run just fine:

c:\Users\Mike\Documents\git\temp\pluginboutique>python
Python 3.5.2 (v3.5.2:4def2a2901a5, Jun 25 2016, 22:18:55) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>

But even then, that is the correct location as is evidenced by:

c:\Users\Mike\Documents\git\temp\pluginboutique>"C:\Program Files\Python35\python.EXE"
Python 3.5.2 (v3.5.2:4def2a2901a5, Jun 25 2016, 22:18:55) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>

And even node will happily run "python" through exec/spawn:

c:\Users\Mike\Documents\git\temp\pluginboutique>node
> var spawn = require('child_process').spawn;
undefined
> var willError = spawn('obviousnonexistentcommand');
undefined
> Error: spawn obviousnonexistentcommand ENOENT
    at exports._errnoException (util.js:1024:11)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:192:19)
    at onErrorNT (internal/child_process.js:374:16)
    at _combinedTickCallback (internal/process/next_tick.js:138:11)
    at process._tickDomainCallback (internal/process/next_tick.js:218:9)
> var python = spawn('python');
undefined
>

[bnoordhuis]

node-gyp (or rather, gyp) needs python 2.7, python 3.x won't work.

[Pomax]

That sounds... weird, in 2017? It's been many, many years by now for codebases to update to something that will run just fine on modern python.

But, if you're right: the error does not in any way mention this, so if that's really the problem the error message needs to be changed here so that users understand what's wrong and can address that.

(I don't use python except for my work, and all that work involves Python 3. so as a JS developer I have no reason to install an older version of Python unless something tells me it needs it)

[refack]

(I don't use python except for my work, and all that work involves Python 3. so as a JS developer I have no reason to install an older version of Python unless something tells me it needs it)

@pomex, I do agree that the error should be more informative. So I opened #1269

Just for general context, for several reasons (which we try very hard to avoid in node) one of which is that python3 is not backwards compatible, python2 and python3 are two separate but equal branches living in parallel.

[vamsi248]

@Pomax same error i am getting how to fix this issue.. did you fixed this issue in your case??

[lalomartins]

In case anyone else lands here looking for the solution to this and wants to subscribe to the Python 3 support issue, it's #1337

[SatishMHiremath]

I have faced and fixed this issue relates node-sass and python error.Try installing latest angular cli command with the steps below

Set the system variable path as well:
C:\Users\windowsusername\AppData\Roaming\npm

C:\Users\windowsusername\AppData\Roaming\npm\node_modules@angular\cli\bin;

C:\Program Files\nodejs;

Then start using angular cli command prompt using:
angular client project folder path>npm install -g @latest

angular client project folder path>npm install -g node-gyp

[LaysDragon]

It looks like the PythonFinder is broken for some reason. It just pop up an error that say it can't find the executable at "C:\Program_Files\Python\Python36\python.exe". This is wired,hah. The executable just here and it just can't find it??? After a little debug,I found it just go into the guessPython function and trying to find the "C:\python27\python.exe" and show with a "C:\Program_Files\Python\Python36\python.exe" misleading error message.

[JonnyWideFoot]

Installing Python 2.7.15 fixed this for me...

[golyalpha]

It's 2018, and this is still an issue.

This issue is becoming even bigger as Python2 is being phased out (It can't even be downloaded from the front page anymore, you have to go through "other downloads" on python.org), this is something that needs fixing.

[Bertware]

There's a PR for this, but the maintainers don't seem to care: #1335

[thorizer]

any news ?

[ivanjx]

THIS IS SO IRRITATING....