lib: print Python executable path using UTF-8 (#2995)

* lib: print Python executable path using UTF-8

The Python executable path may have non-ASCII characters, which can make
the print function fail if the environment encoding is different. This fixes
this issue by using stdout.buffer, which can be used with UTF-8 encoding
for the output, regardless of the environment encoding.

Fixes: https://github.com/nodejs/node-gyp/issues/2829

* fixup! lib: print Python executable path using UTF-8

lib/find-python.js

@@ -41,7 +41,7 @@ class PythonFinder {
   static findPython = (...args) => new PythonFinder(...args).findPython()
 
   log = log.withPrefix('find Python')
-  argsExecutable = ['-c', 'import sys; print(sys.executable);']
+  argsExecutable = ['-c', 'import sys; sys.stdout.buffer.write(sys.executable.encode(\'utf-8\'));']
   argsVersion = ['-c', 'import sys; print("%s.%s.%s" % sys.version_info[:3]);']
   semverRange = '>=3.6.0'
 

test/test-find-python.js

@@ -2,11 +2,14 @@
 
 delete process.env.PYTHON
 
-const { describe, it } = require('mocha')
+const { describe, it, after } = require('mocha')
 const assert = require('assert')
 const PythonFinder = require('../lib/find-python')
 const { execFile } = require('../lib/util')
 const { poison } = require('./common')
+const fs = require('fs')
+const path = require('path')
+const os = require('os')
 
 class TestPythonFinder extends PythonFinder {
   constructor (...args) {
@@ -32,6 +35,32 @@ describe('find-python', function () {
     assert.strictEqual(stderr, '')
   })
 
+  it('find python - encoding', async function () {
+    const found = await PythonFinder.findPython(null)
+    const testFolderPath = fs.mkdtempSync(path.join(os.tmpdir(), 'test-ü-'))
+    const testFilePath = path.join(testFolderPath, 'python.exe')
+    after(function () {
+      try {
+        fs.unlinkSync(testFilePath)
+        fs.rmdirSync(testFolderPath)
+      } catch {}
+    })
+
+    try {
+      fs.symlinkSync(found, testFilePath)
+    } catch (err) {
+      switch (err.code) {
+        case 'EPERM':
+          return assert.fail(err, null, 'Please try to run console as an administrator')
+        default:
+          return assert.fail(err)
+      }
+    }
+
+    const finder = new PythonFinder(testFilePath)
+    await assert.doesNotReject(finder.checkCommand(testFilePath))
+  })
+
   it('find python - python', async function () {
     const f = new TestPythonFinder('python')
     f.execFile = async function (program, args, opts) {