pipina opened a new issue, #36682:
URL: https://github.com/apache/superset/issues/36682
### Bug description
# 🐞 CSV email reports fail with HTTP 500 when using non-default CSV
delimiter (GUI CSV export works)
**Superset version:** Apache Superset 5.0.0
**Deployment:** Helm chart
**Docker image:** `apachesuperset.docker.scarf.sh/apache/superset`
**Base OS:** Debian Bookworm
**Python:** 3.10
**Pandas:** default dependency
**Celery:** enabled (reports/alerts)
**Email reports:** enabled
**Locale:** `sk_SK.UTF-8` (not the root cause, listed for completeness)
**Problem description**
CSV downloads from the Superset GUI work correctly even when `CSV_EXPORT` is
configured with a non-default delimiter (e.g. `;`) and decimal separator (e.g.
`,`). However, CSV email reports fail with an internal server error (HTTP 500).
The failure occurs only in the email reporting workflow and does not affect
manual CSV exports from the UI.
**Configuration used**
```yaml
bootstrapScript: |
#!/bin/bash
apt-get update && \
apt-get install -y locales && \
apt autoremove -y && \
apt clean
localedef -i sk_SK -f UTF-8 sk_SK.UTF-8
rm -rf /var/lib/apt/lists/*
uv pip install Pillow \
psycopg2-binary \
cx_Oracle \
sqlalchemy-vertica-python \
pymssql \
redis==4.6.0 \
openpyxl \
playwright \
&& playwright install-deps \
&& PLAYWRIGHT_BROWSERS_PATH=/usr/local/share/playwright-browsers
playwright install chromium
```
```python
CSV_EXPORT = {
"encoding": "cp1250",
"sep": ";",
"decimal": ","
}
```
**Steps to reproduce**
1. Deploy Apache Superset 5.0.0 using the configuration above.
2. Configure CSV export with a non-default delimiter and decimal separator
as shown.
3. Create a chart with two columns.
4. Download the CSV from the Superset GUI — works correctly.
5. Create and schedule an email report for the same chart with a CSV
attachment.
6. Let the report execute via Celery, or manually trigger the endpoint used
by reports:
```bash
curl -H "Authorization: Bearer $TOKEN" \
"http://superset.superset.svc.cluster.local:8088/api/v1/chart/159/data/?format=csv&type=post_processed&force=false";
```
**Actual behavior**
When the CSV is generated as part of an email report, Superset returns HTTP
500 – Internal Server Error.
Client/API response:
```html
curl -H "Authorization: Bearer $TOKEN"
"http://superset.superset.svc.cluster.local:8088/api/v1/chart/159/data/?format=csv&type=post_processed&force=false";
<!doctype html><html lang="en"><head><meta charset="UTF-8"/><meta
http-equiv="X-UA-Compatible" content="IE=edge"/><meta name="viewport"
content="width=q,initial-scale=1"/><link rel="icon" type="image/png"
href="/static/assets/e3bafb62eb2592c0bb0e.png"/><link
href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500&display=swap";
rel="stylesheet"/><style>html {
height: 100%;
}
body {
color: #1985a0;
font-family: 'Inter', sans-serif;
height: 100%;
margin: 0;
display: flex;
align-items: stretch;
}
h1 {
font-weight: 600;
font-size: 88px;
margin: 0;
}
p {
font-weight: 500;
font-size: 24px;
line-height: 40px;
width: 490px;
}
.button {
-webkit-appearance: button;
-moz-appearance: button;
appearance: button;
background-color: #1985a0; /* Green */
border: none;
color: white;
padding: 16px 38px;
text-align: center;
text-decoration: none;
display: inline-block;
font-size: 11px;
border-radius: 4px;
text-transform: uppercase;
}
.error-page-content {
display: flex;
flex-direction: row;
align-items: center;
justify-content: space-between;
max-width: 1350px;
margin: auto;
width: 100%;
padding: 56px;
}
img {
width: 540px;
}</style><title>500: Internal server error |
Superset</title></head><body><div
class="error-page-content"><section><h1>Internal server error</h1><p>Sorry,
something went wrong. We are fixing the mistake now. Try again later or go back
to home.</p><a href="/" class="button">Back to home</a></section><img alt="500"
src="/static/assets/b01fb73b111d937e4c09.png"
width="540"/></div></body></html>root@superset-worker-695fff8dbb-ssqnv:/app
```
Superset application logs:
```text
2025-12-16 21:11:00,667:WARNING:superset.views.error_handling:Exception
Traceback (most recent call last):
File "/app/.venv/lib/python3.10/site-packages/flask/app.py", line 1484, in
full_dispatch_request
rv = self.dispatch_request()
File "/app/.venv/lib/python3.10/site-packages/flask/app.py", line 1469, in
dispatch_request
return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
File "/app/superset/charts/data/api.py", line 359, in _send_chart_response
result = apply_client_processing(result, form_data, datasource)
File "/app/superset/charts/client_processing.py", line 330, in
apply_client_processing
df = pd.read_csv(StringIO(data))
File
"/app/.venv/lib/python3.10/site-packages/pandas/io/parsers/readers.py", line
912, in read_csv
return _read(filepath_or_buffer, kwds)
File "pandas/_libs/parsers.pyx", line 2029, in
pandas._libs.parsers.raise_parser_error
pandas.errors.ParserError: Error tokenizing data.
C error: Expected 2 fields in line 14, saw 3
```
```text
2025-12-16 21:11:00,668:ERROR:superset.views.error_handling:
Error tokenizing data. C error: Expected 2 fields in line 14, saw 3
```
**Summary**
CSV email reports fail with HTTP 500 due to a Pandas parsing error during
client-side post processing. The issue does not affect CSV downloads from the
GUI and appears isolated to the email/report execution path, where `CSV_EXPORT`
delimiter settings are ignored when CSV data is re-parsed.
### Screenshots/recordings
_No response_
### Superset version
5.0.0
### Python version
3.10
### Node version
16
### Browser
Chrome
### Additional context
_No response_
### Checklist
- [x] I have searched Superset docs and Slack and didn't find a solution to
my problem.
- [x] I have searched the GitHub issue tracker and didn't find a similar bug
report.
- [x] I have checked Superset's logs for errors and if I found a relevant
Python stacktrace, I included it here as text in the "additional context"
section.
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