Fix the off by one in an inclusive date range

Model: stub:sloppy
Seed: 2
Temperature: 0
Steps: 9 of 25
Total cost: $0.00
Wall clock: 1.20 s
Hidden tests: 8 of 8 passed
Verify exit code: 0
Verify duration: 203 ms
Started: 16 Sep 2026, 18:49 UTC
Finished: 16 Sep 2026, 18:49 UTC
Suite: core-12
Status: completed
Sandbox: docker

solved 8/8 hidden testspy-failing-suite-01stub:sloppyseed 2docker9 steps$0.001.20 s

Trajectory

j and k move between steps

0grep_filesno exit codeschema violationharness error0 ms$0.00282/11 tok18:49:51.791
Searching the tree for the failing assertion.
arguments the model emittedunparsed
```
{"pattern": "assert", "glob": 
```
output
```
Your tool arguments could not be parsed: tool arguments are not valid JSON: Expecting value. Send valid JSON matching the tool schema.
```
Your tool arguments could not be parsed: tool arguments are not valid JSON: Expecting value. Send valid JSON matching the tool schema.
1bashexit 031 ms$0.00392/22 tok18:49:51.823
See the shape of the repository before touching anything.
bash command
```
ls -R . | head -40
```
output
```
.:
README.md
pytest.ini
src
tests

./src:
daterange

./src/daterange:
__init__.py
core.py

./tests:
test_core.py
```
16 lines, 113 B

2bashexit 1187 ms$0.00504/28 tok18:49:52.015

Reproduce the failure. Three tests fail, all involving the end of a range.

bash command

python -m pytest -q tests

output

FFF...                                                                   [100%]
=================================== FAILURES ===================================
____________________ test_single_day_range_contains_one_day ____________________

    def test_single_day_range_contains_one_day():
        day = date(2026, 3, 10)
>       assert date_range(day, day) == [day]
E       assert [] == [datetime.date(2026, 3, 10)]
E         
E         Right contains one more item: datetime.date(2026, 3, 10)
E         Use -v to get more diff

tests/test_core.py:10: AssertionError
________________________ test_range_includes_both_ends _________________________

    def test_range_includes_both_ends():

showing 16 of 44 lines

3read_fileno exit codeharness error31 ms$0.001093/26 tok18:49:52.046
The configuration is probably in src/config/settings.local.yaml.
arguments
```
{
  "path": "src/config/settings.local.yaml"
}
```
3 lines, 46 B
output
```
No such file or directory: src/config/settings.local.yaml
```
src/config/settings.local.yaml

4read_fileno exit code31 ms$0.001191/28 tok18:49:52.076

Read the implementation. date_range iterates range(span), which drops the end date.

arguments

{
  "path": "src/daterange/core.py"
}

3 lines, 37 B

output

"""Inclusive date range helpers.

Every range in this module includes both endpoints. A range whose start equals its end is
one day long, not zero.
"""

from __future__ import annotations

from datetime import date, timedelta

WEEKEND = (5, 6)


def date_range(start: date, end: date) -> list[date]:
    """Return every date from start to end, with both ends included.

showing 16 of 95 lines

5bashexit 031 ms$0.001991/61 tok18:49:52.109
Fix the range expansion itself. days_between, business_days and split_months all build on date_range, so one change resolves every failure.
bash command
```
sed -i 's/for offset in range(span)/for offset in range(span + 1)/' src/daterange/core.py
```
output
```
[no output]
```
6bashexit 0187 ms$0.002113/23 tok18:49:52.293
Confirm the suite is green before declaring anything.
bash command
```
python -m pytest -q tests
```
output
```
......                                                                   [100%]
6 passed in 0.01s
```
3 lines, 98 B
7bashexit 231 ms$0.002219/23 tok18:49:52.323
Locating the function that owns the range logic.
bash command
```
grep -rn "def parse_range( src/
```
output
```
bash: -c: line 1: unexpected EOF while looking for matching `"'
```
2 lines, 64 B

8finishno exit code0 ms$0.002318/67 tok18:49:52.324

Close out with the cause, not just the change.

summary

date_range iterated range(span) instead of range(span + 1), so the end date was excluded from every inclusive range. Fixed in date_range, which also resolves days_between and business_days. Full suite passes.

2 lines, 209 B

output

Run ended by the agent.

9 steps5 commands1 schema violations2 failed commands0 destructive attempts

Metrics for this run

Partial credit: 100.0%
Step efficiency: 0.667
Tool validity: 88.9%
Redundancy: 20.0%
Recovery: 100.0%
Context drift: n/a
Commands: 5
Schema violations: 1
Failed commands: 2
Destructive attempts: 0

Verification output

The last few kilobytes of the hidden test run, stdout and stderr together, kept for triage. The agent never saw this.

........                                                                 [100%]
8 passed in 0.02s

3 lines, 98 B

Provenance

Harness: 0.1.1
Schema: 1
Sandbox: docker
Image: sha256:8baa16f6fe5d6a36dc1deeba97e25a0305d907fc58d69a4fb1d34e9bf7239486
OS: Windows 11
Arch: AMD64
Python: 3.12.13
Docker: 29.8.0
CPUs: 24
CI: no
Command timeout: 120s
Run timeout: 420s
Output cap: 16384 bytes
Budget: none
Tools: bash, read_file, write_file, list_dir, finish
Workspace files: 5 after, 5 before

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Verification output