node.js - How to use a different version of python during NPM install?

238
votes

I have terminal access to a VPS running centos 5.9 and default python 2.4.3 installed. I also installed python 2.7.3 via these commands: (I used make altinstall instead of make install)

wget http://www.python.org/ftp/python/2.7.3/Python-2.7.3.tgz
tar -xf Python-2.7.3.tgz
cd Python-2.7.3
./configure
make
make altinstall

then I installed node.js from source via these commands:

python2.7 ./configure
make
make install

The problem is, when I use npm install and try to install a node.js package which requires python > 2.4.3 I get this error:

gyp ERR! configure error
gyp ERR! stack Error: Python executable "python" is v2.4.3, which is not supported by gyp.
gyp ERR! stack You can pass the --python switch to point to Python >= v2.5.0 & < 3.0.0.
gyp ERR! stack     at failPythonVersion (/usr/local/lib/node_modules/npm/node_modules/node-gyp/lib/configure.js:125:14)
gyp ERR! stack     at /usr/local/lib/node_modules/npm/node_modules/node-gyp/lib/configure.js:114:9

how should I "pass the --python switch to point to Python >= v2.5.0"?

6
pythonnode.jscentosnpm
I would propose a hack. How about aliasing this python version inside your shell & then after you close the shell, the system should return to previous state – rafee
@rafee it's great, can you explain how can I do that? I'm a bit new to centos! – Nasser Torabzade
I almost never used CentOS. It should be just like any other linux distribution. I am telling about temporary procedure, because making alias permanent may damage your system. So that shouldn't be done. – rafee
@rafee thanks, I'll check your solution. – Nasser Torabzade
alias python=/path/to/python should be good enough. But be careful about making the change temporary, permanent change may harm your system – rafee

6 Answers

533
votes

You can use --python option to npm like so:

npm install --python=python2.7

or set it to be used always:

npm config set python python2.7

Npm will in turn pass this option to node-gyp when needed.

(note: I'm the one who opened an issue on Github to have this included in the docs, as there were so many questions about it ;-) )

58
votes

set python to python2.7 before running npm install

Linux:

export PYTHON=python2.7

Windows:

set PYTHON=python2.7
38
votes

For Windows users something like this should work:

PS C:\angular> npm install --python=C:\Python27\python.exe
8
votes

Ok, so you've found a solution already. Just wanted to share what has been useful to me so many times;

I have created setpy2 alias which helps me switch python.

alias setpy2="mkdir -p /tmp/bin; ln -s `which python2.7` /tmp/bin/python; export PATH=/tmp/bin:$PATH"

Execute setpy2 before you run npm install. The switch stays in effect until you quit the terminal, afterwards python is set back to system default.

You can make use of this technique for any other command/tool as well.

5
votes

This one works better if you don't have the python on path or want to specify the directory :

//for Windows
npm config set python C:\Python27\python.exe

//for Linux
npm config set python /usr/bin/python27
2
votes

for quick one time use this works, npm install --python="c:\python27"