Use binary exacutable for launching Thonny in macOS app bundle.

Allows getting rid of postinstall script, makes the bundle relocatable, prepares way for publishing dmg instead of pkg, thonny#3283, thonny#2296

packaging/mac/Thonny.app.initial_template/Contents/Resources/launch.py

@@ -0,0 +1,22 @@
+# inspired by IDLE.app/Contents/IDLE
+
+import sys
+import os.path
+
+execdir = os.path.join(os.path.dirname(os.path.dirname(sys.argv[0])), "MacOS")
+executable = os.path.join(execdir, "Python")
+resdir = os.path.join(os.path.dirname(execdir), "Resources")
+libdir = os.path.join(os.path.dirname(execdir), "Frameworks/Python.framework/Versions/3.12/lib")
+ssl_cert_dir = libdir + "/python3.12/site-packages/certifi"
+mainprogram = os.path.join(resdir, "thonnymain.py")
+
+sys.argv.insert(1, mainprogram)
+sys.argv.insert(1, "-I")
+
+os.environ["PYTHON_SYS_EXECUTABLE"] = executable
+os.environ["SSL_CERT_DIR"] = ssl_cert_dir
+os.environ["SSL_CERT_FILE"] = ssl_cert_dir + "/cacert.pem"
+os.environ["TCL_LIBRARY"] = libdir + "/tcl8.6"
+os.environ["TK_LIBRARY"] = libdir + "/tk8.6"
+
+os.execve(executable, sys.argv, os.environ)

packaging/mac/launcher/compile.sh

@@ -0,0 +1,3 @@
+#!/bin/zsh
+
+swiftc -o ../Thonny.app.initial_template/Contents/MacOS/thonny launcher.swift

packaging/mac/launcher/launcher.swift

@@ -0,0 +1,31 @@
+import Foundation
+
+// Get the main bundle path
+let bundlePath = Bundle.main.bundlePath
+
+// Path to the Python interpreter inside the bundle
+let pythonPath = "\(bundlePath)/Contents/Frameworks/Python.framework/Versions/Current/Resources/Python.app/Contents/MacOS/Python"
+
+// Path to the main Python script inside the bundle
+let mainScriptPath = "\(bundlePath)/Contents/Resources/launch.py"
+
+// Ensure Python interpreter and script exist
+let fileManager = FileManager.default
+if fileManager.fileExists(atPath: pythonPath) && fileManager.fileExists(atPath: mainScriptPath) {
+
+    // Prepare arguments (execv expects C-style array of arguments)
+    let arguments = [pythonPath, mainScriptPath]
+    let args = arguments.map { $0.withCString(strdup) }
+
+    // Append nil to the arguments array
+    let argv = args + [nil]
+
+    // Use execv to replace the current process with the Python interpreter
+    execv(argv[0]!, argv)
+
+    // If execv returns, it means there was an error
+    perror("execv failed")
+
+} else {
+    print("Python interpreter or main script not found!")
+}