From efc851a37b27b420dc82bd74bdfe05bfc71c94c8 Mon Sep 17 00:00:00 2001
From: Daniel Han <danielhanchen@gmail.com>
Date: Tue, 10 Feb 2026 06:17:47 -0800
Subject: [PATCH] Fix warmup_ratio deprecation for transformers >= 5.0 (#4019)

* Fix warmup_ratio deprecation warning for transformers >= 5.0

In transformers 5.0, warmup_ratio is deprecated in favor of
warmup_steps which now accepts float values (< 1 = ratio,
>= 1 = absolute steps).

The compiler now conditionally sets warmup_steps=0.1 on
transformers >= 5.0 (same semantics as warmup_ratio=0.1) and
keeps warmup_ratio=0.1 on older versions where warmup_steps
only accepts int.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: Daniel Hanchen <danielhanchen@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
---
 unsloth/models/rl.py | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/unsloth/models/rl.py b/unsloth/models/rl.py
index 32edcebaf8..181e9479df 100755
--- a/unsloth/models/rl.py
+++ b/unsloth/models/rl.py
@@ -76,6 +76,14 @@ try:
 except Exception:
     torch_version = Version("0.0.0")
 
+# Get transformers version for feature detection
+try:
+    from transformers import __version__ as _transformers_version_raw
+
+    transformers_version = Version(_transformers_version_raw)
+except Exception:
+    transformers_version = Version("0.0.0")
+
 
 def vLLMSamplingParams(**kwargs):
     from vllm import SamplingParams
@@ -959,7 +967,6 @@ def _patch_trl_rl_trainers(trainer_file = "grpo_trainer"):
         "per_device_train_batch_size": 4,
         "gradient_accumulation_steps": 2,
         "weight_decay": 0.01,
-        "warmup_ratio": 0.1,
         "seed": 3407,
         "optim": "adamw_8bit",
         "learning_rate": 5e-05,
@@ -986,6 +993,12 @@ def _patch_trl_rl_trainers(trainer_file = "grpo_trainer"):
         # "dataloader_prefetch_factor"    : 2,
         # "dataloader_num_workers"        : 2, # Default is 0 means 1
     }
+    # warmup_ratio deprecated in transformers >= 5.0; warmup_steps accepts float
+    if transformers_version >= Version("5.0.0"):
+        replacements["warmup_steps"] = 0.1
+    else:
+        replacements["warmup_ratio"] = 0.1
+
     for k, v in replacements.items():
         x = f"{k}( = [^,\n]{{1,}})?,\n"
         y = f"'{v}'" if type(v) is str else f"{v}"