[Bug]: create-new-feature.sh rejects the feature descriptions -n, -e and -E, which the Python script accepts #5096

Bug Description

scripts/bash/create-new-feature.sh:93 trims the description with FEATURE_DESCRIPTION=$(echo "$FEATURE_DESCRIPTION" | sed -E ...). When the description is exactly an echo option word (-n, -e, -E, or a combination such as -neE), bash's builtin echo treats it as an option and prints nothing. The script then exits 1 with "Feature description cannot be empty or contain only whitespace". The Python twin, scripts/python/create_new_feature.py, accepts the same input and creates 001-n. The two variants therefore disagree.

Steps to Reproduce

From a fresh clone, after uv sync, save the script below and run uv run python -I repro.py from the repository root. It copies both script variants into a temporary project and runs them with --json --dry-run.

import shutil, subprocess, sys, tempfile
from pathlib import Path

repo = Path(tempfile.mkdtemp())
for sub, files in [("bash", ["common.sh", "create-new-feature.sh"]),
                   ("python", ["common.py", "create_new_feature.py"])]:
    d = repo / ".specify" / "scripts" / sub
    d.mkdir(parents=True)
    for f in files:
        shutil.copy(Path("scripts") / sub / f, d / f)

for desc in ["-n", "-e", "-E", "-neE"]:
    for name, cmd in [
        ("bash", ["bash", ".specify/scripts/bash/create-new-feature.sh"]),
        ("python", [sys.executable, ".specify/scripts/python/create_new_feature.py"]),
    ]:
        r = subprocess.run(cmd + ["--json", "--dry-run", desc], cwd=repo,
                           capture_output=True, text=True)
        out = (r.stdout or r.stderr).strip()
        print(f"{desc:5} {name:6} rc={r.returncode} {out[:80]}")

Expected Behavior

Both variants should treat the description as text and produce the same branch name (for example 001-n). The bash script's own comment at scripts/bash/create-new-feature.sh:220-221 says it uses "printf instead of echo, so a name of "-n"/"-e"/"-E" is text, not options". tests/test_create_new_feature_python_parity.py asserts that the variants produce identical output (for example lines 444 and 752).

Actual Behavior

-n    bash   rc=1 Error: Feature description cannot be empty or contain only whitespace
-n    python rc=0 {"BRANCH_NAME":"001-n","SPEC_FILE":"/tmp/tmpimfdrmab/specs/001-n/spec.md","FEATU
-e    bash   rc=1 Error: Feature description cannot be empty or contain only whitespace
-e    python rc=0 {"BRANCH_NAME":"001-e","SPEC_FILE":"/tmp/tmpimfdrmab/specs/001-e/spec.md","FEATU
-E    bash   rc=1 Error: Feature description cannot be empty or contain only whitespace
-E    python rc=0 {"BRANCH_NAME":"001-e","SPEC_FILE":"/tmp/tmpimfdrmab/specs/001-e/spec.md","FEATU
-neE  bash   rc=1 Error: Feature description cannot be empty or contain only whitespace
-neE  python rc=0 {"BRANCH_NAME":"001-nee","SPEC_FILE":"/tmp/tmpimfdrmab/specs/001-nee/spec.md","F

Specify CLI Version

1.2.4.dev0 (main at 27d14e2)

AI Agent

Not applicable

Operating System

Linux 6.18 (Ubuntu container)

Python Version

Python 3.12.3

Error Logs

Error: Feature description cannot be empty or contain only whitespace

Additional Context

Using printf '%s\n' "$FEATURE_DESCRIPTION" on line 93 would match the approach the script already uses elsewhere.

A smaller related parity gap: for a single empty argument (create-new-feature.sh ""), bash prints the Usage line, while the Python script prints "Error: Feature description cannot be empty or contain only whitespace" (scripts/python/create_new_feature.py:150-156). Both exit 1.

Also reproduced on macOS (Darwin 25.6, arm64) with Python 3.14.4 and uv run python -I repro.py against 27d14e2; the output matches the above.

AI Disclosure

Found and reproduced with Claude Code (model: Claude Opus 4.8), run autonomously under human supervision. The human reporter re-ran every reproduction above before filing.