TMC_LANGS_PYTHON_EXEC for overriding python executable

Author: Heliozoa

tmc-langs-python3/README.md

@@ -0,0 +1,5 @@
+## Environment variables
+
+| var name                | usage                       |
+| ----------------------- | --------------------------- |
+| `TMC_LANGS_PYTHON_EXEC` | Sets the Python executable. |

tmc-langs-python3/src/lib.rs

@@ -18,11 +18,17 @@ enum LocalPy {
     Unix,
     Windows,
     WindowsConda { conda_path: String },
+    Custom { python_exec: String },
 }
 
 lazy_static! {
     // the python command is platform-dependent
     static ref LOCAL_PY: LocalPy = {
+        if let Ok(python_exec) = env::var("TMC_LANGS_PYTHON_EXEC") {
+            log::debug!("using Python from environment variable TMC_LANGS_PYTHON_EXEC={}", python_exec);
+            return LocalPy::Custom { python_exec };
+        }
+
         if cfg!(windows) {
             // Check for Conda
             let conda = env::var("CONDA_PYTHON_EXE");

tmc-langs-python3/src/plugin.rs

@@ -49,12 +49,7 @@ impl LanguagePlugin for Python3Plugin {
         path: &Path,
         timeout: Option<Duration>,
     ) -> Result<RunResult, TmcError> {
-        let run_result = run_tmc_command(path, &[], timeout);
-
-        if let Err(error) = run_result {
-            log::error!("Failed to parse exercise description. {}", error);
-        }
-
+        run_tmc_command(path, &[], timeout)?;
         Ok(parse_test_result(path)?)
     }
 
@@ -98,11 +93,13 @@ fn run_tmc_command(
         LocalPy::Unix => ("python3", Command::new("python3")),
         LocalPy::Windows => ("py", Command::new("py")),
         LocalPy::WindowsConda { conda_path } => ("conda", Command::new(conda_path)),
+        LocalPy::Custom { python_exec } => (python_exec.as_str(), Command::new(python_exec)),
     };
     let command = match &*LOCAL_PY {
         LocalPy::Unix => &mut command,
         LocalPy::Windows => command.args(&["-3"]),
         LocalPy::WindowsConda { .. } => &mut command,
+        LocalPy::Custom { .. } => &mut command,
     };
     let command = command
         .args(&common_args)