fix(python): remove hardcoded OTEL_LOG_LEVEL=DEBUG that caused stderr deadlocks

Per #3357, `python.runScript()` deadlocks any Python subprocess
that writes more than ~64KB to stderr. The previous implementation
hardcoded `OTEL_LOG_LEVEL: 'DEBUG'` in the subprocess environment,
which caused OTEL-aware Python libraries (mlflow, opentelemetry-sdk,
etc.) to emit verbose debug-level logs to stderr during import.

Once stderr exceeded the OS pipe buffer, the Python process would
block on its next `write()` syscall indefinitely — a silent,
permanent hang with no error or timeout (unless `maxDuration` was
set).

Remove the hardcoded `OTEL_LOG_LEVEL: 'DEBUG'`. This brings
`runScript()` in line with `run()`, `runInline()`, and the
streaming variants — none of which set `OTEL_LOG_LEVEL`. The
original line was almost certainly leftover dev instrumentation
that shipped accidentally.

Closes #3357

Author: SAY-5

.changeset/python-stderr-deadlock-fix.md

@@ -0,0 +1,5 @@
+---
+"@trigger.dev/python": patch
+---
+
+Fix `python.runScript()` deadlock when the Python subprocess produces more than ~64KB of stderr output. The previous implementation hardcoded `OTEL_LOG_LEVEL: "DEBUG"` in the subprocess environment, which caused OTEL-aware Python libraries (mlflow, opentelemetry-sdk, etc.) to emit verbose debug-level logging to stderr during import. Once stderr exceeded the OS pipe buffer, the Python process would block on `write()` indefinitely. Removing the hardcoded debug log level brings `runScript()` in line with `run()`, `runInline()`, and the streaming variants — none of which set `OTEL_LOG_LEVEL`.

packages/python/src/index.ts

@@ -97,7 +97,6 @@ export const python = {
                 }=trigger,${Object.entries(taskContext.attributes)
                   .map(([key, value]) => `${key}=${value}`)
                   .join(",")}`,
-                OTEL_LOG_LEVEL: "DEBUG",
               },
             },
             throwOnError: false,