# Internal TileDB uncaught exception; basic\_string::compare:
**URL:** https://forum.tiledb.com/t/internal-tiledb-uncaught-exception-basic-string/267
**Category:** Uncategorized
**Created:** [November 6, 2020, 11:11am UTC](https://forum.tiledb.com/t/internal-tiledb-uncaught-exception-basic-string/267 "2020-11-06T11:11:20Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@ilveroluca](https://forum.tiledb.com/u/ilveroluca)
#### Post date: [November 6, 2020, 11:11am UTC](https://forum.tiledb.com/t/internal-tiledb-uncaught-exception-basic-string/267/1 "2020-11-06T11:11:20Z")
Hi,
I’m trying to port a Python program from an HDFS back end to S3. Running some simple tests I’m getting an uncaught exception from TileDB. As s3 back ends, I have tried both minio and the Ceph object store. Here’s an example with a stack trace from pytest:
```auto
def test_basic_tiledb_s3_operativity(clean_s3):
import tiledb
uri = 's3://firstbucket/basic-tiledb-s3-operativity'
config = tiledb.Config(params={
'vfs.s3.aws_access_key_id': 'tdm-user',
'vfs.s3.aws_secret_access_key': 'tdm-user-s3',
'vfs.s3.endpoint_override': 'minio:9000',
'vfs.s3.scheme': 'http',
'vfs.s3.region': '',
'vfs.s3.verify_ssl': 'false',
'vfs.s3.use_virtual_addressing': 'false',
'vfs.s3.use_multipart_upload': 'false'})
ctx = tiledb.Ctx(config=config)
a = np.arange(5)
logging.debug("trying to write array to s3: %s", uri)
schema = tiledb.schema_like(a, ctx=ctx)
> tiledb.DenseArray.create(uri, schema)
tests/client/test_non_scalar_source.py:131:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
tiledb/libtiledb.pyx:3697: in tiledb.libtiledb.Array.create
???
tiledb/libtiledb.pyx:481: in tiledb.libtiledb._raise_ctx_err
???
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
> ???
E tiledb.libtiledb.TileDBError: Error: Internal TileDB uncaught exception; basic_string::compare: __pos (which is 18446744073709551615) > this->size() (which is 4)
tiledb/libtiledb.pyx:466: TileDBError
```
In other test, the same unhandled exception is raised from `tiledb.object_type(uri, context)`. While the stack trace in that case is different, the exception message is identical:
```
tiledb.libtiledb.TileDBError: Error: Internal TileDB uncaught exception; basic_string::compare: __pos (which is 18446744073709551615) > this->size() (which is 4)
```
TileDB version: 0.7.0
I’m running in docker. I have built my own image and installed tiledb with `pip`.
Any hints?
Thanks,
Luca
---
### Author:  [@ilveroluca](https://forum.tiledb.com/u/ilveroluca)
#### Post date: [November 6, 2020, 11:55am UTC](https://forum.tiledb.com/t/internal-tiledb-uncaught-exception-basic-string/267/2 "2020-11-06T11:55:12Z")
I’ll add a detail that seems relevant: sometimes, this test passes.
My complete test scenario first executes a function that uses boto to delete any objects in the s3 bucket (that’s the `clean_s3` pytest fixture left in the code I pasted), then executes the test function. If I launch the test a few times in quick succession, the first time it’ll pass; subsequent attempts all fail with the same exception.
---
### Author:  [@joe\_maley](https://forum.tiledb.com/u/joe_maley)
#### Post date: [November 6, 2020, 1:45pm UTC](https://forum.tiledb.com/t/internal-tiledb-uncaught-exception-basic-string/267/3 "2020-11-06T13:45:23Z")
Hi @ilveroluca –
Thanks for the report. I’m working on reproducing this to see what’s going wrong. I’ll let you know once I have an update.
---
### Author:  [@ilveroluca](https://forum.tiledb.com/u/ilveroluca)
#### Post date: [November 6, 2020, 2:31pm UTC](https://forum.tiledb.com/t/internal-tiledb-uncaught-exception-basic-string/267/4 "2020-11-06T14:31:32Z")
Hi Joe,
I opened an issue on Github with a smaller code snipped sufficient to reproduce the problem. Here’s the link: [https://github.com/TileDB-Inc/TileDB-Py/issues/409](https://github.com/TileDB-Inc/TileDB-Py/issues/409)
Since posting, I have confirmed that TileDB 0.6.1 doesn’t have the issue (I tried both your docker image on DockerHub and I rebuilt my own). I’m currently working on testing TileDB 0.6.6.
---
### Author:  [@ilveroluca](https://forum.tiledb.com/u/ilveroluca)
#### Post date: [November 6, 2020, 2:33pm UTC](https://forum.tiledb.com/t/internal-tiledb-uncaught-exception-basic-string/267/5 "2020-11-06T14:33:34Z")
0.6.6 also works. It looks like a regression in 0.7.0.