Derive program name from venv if possible

filmor · filmor · commit 51d6aa823ed6 · 2025-10-25T11:10:59.000+02:00
diff --git a/src/runtime/Runtime.cs b/src/runtime/Runtime.cs
@@ -96,6 +96,42 @@ internal static int GetRun()
             return runNumber;
         }
 
+        static void EnsureProgramName()
+        {
+            if (!string.IsNullOrEmpty(PythonEngine.ProgramName))
+                return;
+
+            string fromEnv = Environment.GetEnvironmentVariable("PYTHONNET_PYEXE");
+            if (!string.IsNullOrEmpty(fromEnv))
+            {
+                PythonEngine.ProgramName = fromEnv;
+                return;
+            }
+
+            string venv = Environment.GetEnvironmentVariable("VIRTUAL_ENV");
+            if (!string.IsNullOrEmpty(venv))
+            {
+                if (IsWindows)
+                {
+                    var path = Path.Combine(venv, "Scripts", "python.exe");
+                    if (System.IO.File.Exists(path))
+                    {
+                        PythonEngine.ProgramName = path;
+                        return;
+                    }
+                }
+                else
+                {
+                    var path = Path.Combine(venv, "bin", "python");
+                    if (System.IO.File.Exists(path))
+                    {
+                        PythonEngine.ProgramName = path;
+                        return;
+                    }
+                }
+            }
+        }
+
         internal static bool HostedInPython;
         internal static bool ProcessIsTerminating;
 
@@ -117,6 +153,8 @@ internal static void Initialize(bool initSigs = false)
             );
             if (!interpreterAlreadyInitialized)
             {
+                EnsureProgramName();
+
                 Py_InitializeEx(initSigs ? 1 : 0);
 
                 NewRun();
