From f880655e32793ce50fec5a63040d041c29b7d2dc Mon Sep 17 00:00:00 2001
From: Ruben Fiszel <ruben@windmill.dev>
Date: Mon, 26 Jan 2026 15:15:48 +0000
Subject: [PATCH] fix: set 3.12 as python fallback if no version explicitely
 set

---
 backend/windmill-worker/src/python_executor.rs |  2 +-
 backend/windmill-worker/src/python_versions.rs | 13 +++++++++----
 backend/windmill-worker/src/worker.rs          | 13 +++++++++----
 3 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/backend/windmill-worker/src/python_executor.rs b/backend/windmill-worker/src/python_executor.rs
index 9cf4f7046d..6572568a1d 100644
--- a/backend/windmill-worker/src/python_executor.rs
+++ b/backend/windmill-worker/src/python_executor.rs
@@ -2396,7 +2396,7 @@ for line in sys.stdin:
         PyV::parse_from_requirements(&split_python_requirements(requirements.as_str()))
     } else {
         tracing::warn!(workspace_id = %w_id, "lockfile is empty for dedicated worker, thus python version cannot be inferred. Fallback to 3.11");
-        PyVAlias::Py311.into()
+        PyVAlias::default().into()
     };
 
     let python_path = py_version
diff --git a/backend/windmill-worker/src/python_versions.rs b/backend/windmill-worker/src/python_versions.rs
index 0b8d7da6ef..debe54ebf0 100644
--- a/backend/windmill-worker/src/python_versions.rs
+++ b/backend/windmill-worker/src/python_versions.rs
@@ -373,7 +373,7 @@ impl PyV {
             // If there is no assigned version in lockfile we automatically fallback to 3.11
             // In this case we have dependencies or other metadata, but no associated python version
             // This is the case for old deployed scripts
-            PyVAlias::Py311.into(),
+            PyVAlias::default().into(),
         )
     }
 
@@ -449,6 +449,7 @@ impl PyV {
         }
         res
     }
+
     async fn get_python_inner(
         &self,
         job_id: &Uuid,
@@ -462,20 +463,24 @@ impl PyV {
         let py_path = self.find_python().await;
 
         // Runtime is not installed
-        if py_path.is_err() {
+        if let Err(py_err) = py_path {
             // Install it
             if let Err(err) = self
                 .install_python(job_id, mem_peak, conn, worker_name, w_id, occupancy_metrics)
                 .await
             {
-                tracing::error!("Cannot install python: {err}");
+                tracing::error!(
+                    "Cannot install python: {err}, after runtime wasn't found: {py_err}"
+                );
                 return Err(err);
             } else {
                 // Try to find one more time
                 let py_path = self.find_python().await;
 
                 if let Err(err) = py_path {
-                    tracing::error!("Cannot find python version {err}");
+                    tracing::error!(
+                        "Cannot find python version {err} after runtime wasn't found: {py_err}"
+                    );
                     return Err(err);
                 }
 
diff --git a/backend/windmill-worker/src/worker.rs b/backend/windmill-worker/src/worker.rs
index 5cc4972c32..117c051266 100644
--- a/backend/windmill-worker/src/worker.rs
+++ b/backend/windmill-worker/src/worker.rs
@@ -637,7 +637,9 @@ pub async fn is_otel_tracing_proxy_enabled_for_lang(lang: &ScriptLang) -> bool {
 /// Get proxy environment variables for job execution for a specific language.
 /// When OTEL tracing proxy is enabled for this language, routes all traffic through the proxy.
 /// Otherwise, uses the standard HTTP_PROXY/HTTPS_PROXY from environment.
-pub async fn get_proxy_envs_for_lang(lang: &ScriptLang) -> anyhow::Result<Vec<(&'static str, String)>> {
+pub async fn get_proxy_envs_for_lang(
+    lang: &ScriptLang,
+) -> anyhow::Result<Vec<(&'static str, String)>> {
     #[cfg(all(feature = "private", feature = "enterprise"))]
     if is_otel_tracing_proxy_enabled_for_lang(lang).await {
         return get_otel_tracing_proxy_envs().await;
@@ -664,7 +666,10 @@ async fn get_otel_tracing_proxy_envs() -> anyhow::Result<Vec<(&'static str, Stri
         // CA cert for various runtimes to trust the tracing proxy
         ("SSL_CERT_FILE", TRACING_PROXY_CA_CERT_PATH.to_string()),
         ("REQUESTS_CA_BUNDLE", TRACING_PROXY_CA_CERT_PATH.to_string()),
-        ("NODE_EXTRA_CA_CERTS", TRACING_PROXY_CA_CERT_PATH.to_string()),
+        (
+            "NODE_EXTRA_CA_CERTS",
+            TRACING_PROXY_CA_CERT_PATH.to_string(),
+        ),
         ("CURL_CA_BUNDLE", TRACING_PROXY_CA_CERT_PATH.to_string()),
         ("DENO_CERT", TRACING_PROXY_CA_CERT_PATH.to_string()),
     ])
@@ -1291,7 +1296,7 @@ pub async fn run_worker(
                     "Cannot preinstall or find Instance Python version to worker: {e}"//
                 );
             }
-            if let Err(e) = PyV::from(PyVAlias::Py311)
+            if let Err(e) = PyV::from(PyVAlias::default())
                 .try_get_python(&Uuid::nil(), &mut 0, &conn, &worker_name, "", &mut None)
                 .await
             {
@@ -1299,7 +1304,7 @@ pub async fn run_worker(
                     worker = %worker_name,
                     hostname = %hostname,
                     worker_dir = %worker_dir,
-                    "Cannot preinstall or find default 311 version to worker: {e}"//
+                    "Cannot preinstall or find default version to worker: {e}"//
                 );
             }
         });