# Hail 0.2.5 patch notes

**URL:** <https://discuss.hail.is/t/hail-0-2-5-patch-notes/798>\
**Category:** Updates\
**Created:** [December 7, 2018, 5:16pm UTC](https://discuss.hail.is/t/hail-0-2-5-patch-notes/798 "2018-12-07T17:16:07Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![tpoterba](https://yyz2.discourse-cdn.com/flex036/user_avatar/discuss.hail.is/tpoterba/32/61_2.png) [@tpoterba](https://discuss.hail.is/u/tpoterba)\
**Post date:** [December 7, 2018, 5:16pm UTC](https://discuss.hail.is/t/hail-0-2-5-patch-notes/798/1 "2018-12-07T17:16:07Z")

</div>

## 0.2.5

Released 2018-12-07

### New features

- ([#4845](https://github.com/hail-is/hail/pull/4845)) The [or\_error](https://hail.is/docs/0.2/functions/core.html#hail.expr.builders.CaseBuilder.or_error) method in `hl.case` and `hl.switch` statements now takes a string expression rather than a string literal, allowing more informative messages for errors and assertions.
- ([#4865](https://github.com/hail-is/hail/pull/4865)) We use this new `or_error` functionality in methods that require biallelic variants to include an offending variant in the error message.
- ([#4820](https://github.com/hail-is/hail/pull/4820)) Added [hl.reversed](https://hail.is/docs/0.2/functions/collections.html?highlight=reversed#hail.expr.functions.reversed) for reversing arrays and strings.
- ([#4895](https://github.com/hail-is/hail/pull/4895)) Added `include_strand` option to the [hl.liftover](https://hail.is/docs/0.2/functions/genetics.html?highlight=liftover#hail.expr.functions.liftover) function.

### Performance improvements

- ([#4907](https://github.com/hail-is/hail/pull/4907))([#4911](https://github.com/hail-is/hail/pull/4911)) Addressed one aspect of bad scaling in enormous literal values (triggered by a list of 300,000 sample IDs) related to logging.
- ([#4909](https://github.com/hail-is/hail/pull/4909))([#4914](https://github.com/hail-is/hail/pull/4914)) Fixed a check in Table/MatrixTable initialization that scaled O(n^2) with the total number of fields.

### Bug fixes

- ([#4754](https://github.com/hail-is/hail/pull/4754))([#4799](https://github.com/hail-is/hail/pull/4799)) Fixed optimizer assertion errors related to certain types of pipelines using `group_rows_by`.
- ([#4888](https://github.com/hail-is/hail/pull/4888)) Fixed assertion error in BlockMatrix.sum.
- ([#4871](https://github.com/hail-is/hail/pull/4871)) Fixed possible error in locally sorting nested collections.
- ([#4889](https://github.com/hail-is/hail/pull/4889)) Fixed break in compatibility with extremely old MatrixTable/Table files.
- ([#4527](https://github.com/hail-is/hail/pull/4527))([#4761](https://github.com/hail-is/hail/pull/4761)) Fixed optimizer assertion error sometimes encountered with `hl.split_multi[_hts]`.