* studio: extend offline DNS auto-detect to inference parent + training
#5505 fixed the GGUF/llama-server load path. Studio still has two
adjacent code paths that burn ~30-60s of soft-failed timeouts before
the worker subprocess starts when DNS to huggingface.co is dead and
the model is already in the local HF cache.
Inference parent process (routes/inference.py:load_model):
* ModelConfig.from_identifier now runs inside _hf_offline_if_dns_dead
so the LoRA-detect hf_model_info call and the urllib config probes
in utils/transformers_version.py short-circuit when DNS is dead.
* utils/models/model_config.py: extracted the inline HF_HUB_OFFLINE/
TRANSFORMERS_OFFLINE check used by list_gguf_variants and
detect_gguf_model_remote into a shared _env_offline() helper, then
reused it to gate the LoRA-detect hf_model_info call.
* utils/transformers_version.py: _check_tokenizer_config_needs_v5 and
_check_config_needs_550 now early-return False when offline instead
of issuing a 10s urllib.urlopen against huggingface.co/raw/main.
Training worker (core/training/worker.py:run_training_process):
* Add the same 2s DNS probe used by core/inference/worker.py at the
top of the training subprocess. On failure, set HF_HUB_OFFLINE,
TRANSFORMERS_OFFLINE, and HF_DATASETS_OFFLINE before the rest of
the subprocess imports torch/transformers/unsloth, so every
from_pretrained, snapshot_download, and load_dataset call below
resolves from cache. Scope is per-subprocess; the orchestrator
always spawns a fresh worker per training run.
Training trainer (core/training/trainer.py:load_model):
* Skip the proactive hf_model_info gated-repo probe when _env_offline()
is true. The API is unreachable anyway, and a gated model that is
already cached is exactly the scenario the user is trying to train
against. from_pretrained surfaces the real error if access is
actually denied.
Tests (tests/test_offline_inference_parent.py, 7 new cases):
* _env_offline truthy/falsy parsing across HF_HUB_OFFLINE and
TRANSFORMERS_OFFLINE.
* transformers_version urllib short-circuit when offline.
* LoRA detect hf_model_info skip when offline.
Existing tests/test_offline_gguf_cache_fallback.py still passes
(26 cases) because the inline env check was extracted, not changed.
* tests: prefer real httpx over stub in offline-test files
The studio test stub convention only included the 6 httpx exception
names that existed callers needed. Newer huggingface_hub (1.15+)
imports HTTPError, Response, Request, HTTPStatusError, AsyncClient,
and more at module import time. When httpx is truly absent the stub
chase becomes a treadmill.
Use the real package when installed (the CI install list already
includes httpx, so this is the production environment). Fall back to
the stub only when httpx is genuinely missing.
No code under test changes.
* studio: detect cached LoRA adapters offline; tighten test
Two follow-ups from the review pass on #5512:
* ModelConfig.from_identifier no longer skips the remote LoRA-detect
hf_model_info call when _env_offline() is true. huggingface_hub
short-circuits the call via OfflineModeIsEnabled in ~0ms when
HF_HUB_OFFLINE is set, so the original 25s concern was moot once
routes/inference.py wrapped the call in _hf_offline_if_dns_dead.
Skipping the API meant users with a cached LoRA adapter
(adapter_config.json on disk) got is_lora=False and the load
failed. After the API call (which raises fast offline) a new
cache-fallback walks the HF cache snapshot for adapter_config.json
via the existing _iter_hf_cache_snapshots helper.
* test_hf_model_info_not_called_when_offline replaced. The old test
raised AssertionError inside production code that catches Exception,
so it passed even if the call happened. New tests use MagicMock and
assert call_count >= 1, plus a fixture that stages a fake HF cache
with adapter_config.json to verify the offline cache detection.
Test count goes from 7 to 8 in test_offline_inference_parent.py.
Combined with test_offline_gguf_cache_fallback.py: 34 pass in 9.75s.
* Fix/adjust offline training DNS probe per PR #5505 review
Same fix as #5505's _probe_dns_dead refactor: run gethostbyname on a
daemon thread with join timeout so concurrent sockets in the parent
interpreter never inherit a process-wide socket.setdefaulttimeout
mutation. Adds a static-pin regression test that the inference parent
file does not regress on this.
* [pre-commit.ci] auto fixes from pre-commit.com hooks
for more information, see https://pre-commit.ci
* Trim verbose code comments per review feedback
Shorten the longer explanatory comments added by this PR while keeping
the WHY of each non-obvious branch:
- trainer.py: collapse the 5-line proactive gated-check comment.
- training/worker.py: trim the offline auto-detect preamble and the
"logger isn't configured" note.
- routes/inference.py: shorten the DNS-probe wrap rationale.
- transformers_version.py: collapse the two urllib short-circuit notes.
- model_config.py: shorten the LoRA detect + cache-fallback notes.
- tests/test_offline_inference_parent.py: tighter module docstring,
trim class docstrings, drop multi-line explainer comments inside the
tests; behaviour and coverage unchanged (9/9 tests still pass).
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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
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