I've been looking for the answer to this for a good solid week now, with no success. I've looked at every StackOverflow post, every article from Google and every related Github issue I could find. Most related errors seem to be older, so I'm wondering if my issue is slightly different due to me being on macOS Big Sur.

The issue: When I try to run yarn install in my local repo, I receive an error related to node-gyp and a python executable that is unable to be found. Here is what my terminal shows:

yarn install v1.22.17

...other stuff

[4/4] 🔨  Building fresh packages...
[6/13] ⠐ node-sass
[2/13] ⠐ node-sass
[10/13] ⠐ metrohash
[4/13] ⠐ fsevents
error /Users/jimmiejackson/Documents/repositories/repo-name/node_modules/metrohash: Command failed.
Exit code: 1
Command: node-gyp rebuild
Arguments:
Directory: /Users/jimmiejackson/Documents/repositories/repo-name/node_modules/metrohash
Output:
gyp info it worked if it ends with ok
gyp info using node-gyp@3.8.0
gyp info using node@12.18.0 | darwin | x64
gyp ERR! configure error
gyp ERR! stack Error: Can't find Python executable "/usr/local/opt/python@3.9/bin/python3", you can set the PYTHON env variable.
gyp ERR! stack     at PythonFinder.failNoPython (/Users/jimmiejackson/Documents/repositories/repo-name/node_modules/node-gyp/lib/configure.js:484:19)
gyp ERR! stack     at PythonFinder.<anonymous> (/Users/jimmiejackson/Documents/repositories/repo-name/node_modules/node-gyp/lib/configure.js:406:16)
gyp ERR! stack     at F (/Users/jimmiejackson/Documents/repositories/repo-name/node_modules/which/which.js:68:16)
gyp ERR! stack     at E (/Users/jimmiejackson/Documents/repositories/repo-name/node_modules/which/which.js:80:29)
gyp ERR! stack     at /Users/jimmiejackson/Documents/repositories/repo-name/node_modules/which/which.js:89:16
gyp ERR! stack     at /Users/jimmiejackson/Documents/repositories/repo-name/node_modules/isexe/index.js:42:5
gyp ERR! stack     at /Users/jimmiejackson/Documents/repositories/repo-name/node_modules/isexe/mode.js:8:5
gyp ERR! stack     at FSReqCallback.oncomplete (fs.js:167:21)
gyp ERR! System Darwin 20.6.0
gyp ERR! command "/Users/jimmiejackson/.nvm/versions/node/v12.18.0/bin/node" "/Users/jimmiejackson/Documents/repositories/repo-name/node_modules/metrohash/node_modules/.bin/node-gyp" "rebuild"
gyp ERR! cwd /Users/jimmiejackson/Documents/repositories/repo-name/node_modules/metrohash

I'm not entirely sure what this error means or why this node module is searching for python3. I've tried running npm set config /path/to/python, downloading python3, setting the PYTHON path in my .zshrc profile, but nothing seems to be working. It's entirely possible that my lack of understanding of the issue means that I'm on the right path but didn't quite get something right. Any ideas?

Reading the gyp-node source might helps. Here are some steps you can try.

1. Install python2. You should make sure that in the terminal, which -a python2 only returns one python2 and python2 -V returns the correct 2.x version.

2. override PYTHON env. export PYTHON=python2.

3. Rerun the install.

If there's still an error, probably the error message is different.