fix error messages on import with broken build
There is some disagreement over whether this should close #18089, the canonical answer being "no".  This at least makes it slightly less bad.

> There is some disagreement over whether this should close #18089

No, there isn't any disagreement on our end.  We're telling you that this message alone will not be sufficient and that even if this PR is merged, we will not close the issue. # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=h1) Report
> Merging [#18098](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/27bbea7ee125f4dc19dca2a7703c9a13ca754f9b?src=pr&el=desc) will **decrease** coverage by `0.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/18098/graphs/tree.svg?src=pr&token=eZ4WkYLtcO&width=650&height=150)](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #18098      +/-   ##
==========================================
- Coverage   91.25%   91.23%   -0.02%     
==========================================
  Files         163      163              
  Lines       50120    50120              
==========================================
- Hits        45737    45728       -9     
- Misses       4383     4392       +9
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.04% <ø> (ø)` | :arrow_up: |
| #single | `40.32% <ø> (-0.06%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.75% <0%> (-0.1%)` | :arrow_down: |
| [pandas/tests/indexes/timedeltas/\_\_init\_\_.py](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=tree#diff-cGFuZGFzL3Rlc3RzL2luZGV4ZXMvdGltZWRlbHRhcy9fX2luaXRfXy5weQ==) | `92.3% <0%> (ø)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/18098?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/18098?src=pr&el=footer). Last update [27bbea7...7c478d7](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=h1) Report
> Merging [#18098](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/27bbea7ee125f4dc19dca2a7703c9a13ca754f9b?src=pr&el=desc) will **decrease** coverage by `0.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/18098/graphs/tree.svg?width=650&height=150&src=pr&token=eZ4WkYLtcO)](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #18098      +/-   ##
==========================================
- Coverage   91.25%   91.23%   -0.02%     
==========================================
  Files         163      163              
  Lines       50120    50120              
==========================================
- Hits        45737    45728       -9     
- Misses       4383     4392       +9
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.04% <ø> (ø)` | :arrow_up: |
| #single | `40.32% <ø> (-0.06%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.75% <0%> (-0.1%)` | :arrow_down: |
| [pandas/tests/indexes/timedeltas/\_\_init\_\_.py](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=tree#diff-cGFuZGFzL3Rlc3RzL2luZGV4ZXMvdGltZWRlbHRhcy9fX2luaXRfXy5weQ==) | `92.3% <0%> (ø)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/18098?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/18098?src=pr&el=footer). Last update [27bbea7...7c478d7](https://codecov.io/gh/pandas-dev/pandas/pull/18098?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 > No, there isn't any disagreement on our end. We're telling you that this message alone will not be sufficient and that even if this PR is merged, we will not close the issue.

Buddy, no need to get snippy.  See the original comment, I acknowledged that I don't get a vote in this. > Buddy, no need to get snippy. See the original comment, I acknowledged that I don't get a vote in this.

My bad if it came across that way.  I was trying to make it clear that this wasn't really a point of contention, which is what your PR description made it sound like.