[wip] debug failures
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22038?src=pr&el=h1) Report
> Merging [#22038](https://codecov.io/gh/pandas-dev/pandas/pull/22038?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/a43947283dd6dc9f9dc2742700c7fa4677d7e27a?src=pr&el=desc) will **not change** coverage.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/22038/graphs/tree.svg?token=eZ4WkYLtcO&src=pr&width=650&height=150)](https://codecov.io/gh/pandas-dev/pandas/pull/22038?src=pr&el=tree)

```diff
@@           Coverage Diff           @@
##           master   #22038   +/-   ##
=======================================
  Coverage      92%      92%           
=======================================
  Files         170      170           
  Lines       50607    50607           
=======================================
  Hits        46559    46559           
  Misses       4048     4048
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.4% <ø> (ø)` | :arrow_up: |
| #single | `42.19% <ø> (ø)` | :arrow_up: |


------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22038?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22038?src=pr&el=footer). Last update [a439472...43545ec](https://codecov.io/gh/pandas-dev/pandas/pull/22038?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 Is the idea here to track down the warnings that occasionally make Travis fail? closing as fixed