id,node_id,number,state,locked,title,user,body,created_at,updated_at,closed_at,merged_at,merge_commit_sha,assignee,milestone,draft,head,base,author_association,auto_merge,repo,url,merged_by
172568671,MDExOlB1bGxSZXF1ZXN0MTcyNTY4Njcx,1953,closed,0,Fix maybe_promote,1997005,"With tests for every possible dtype:

(numpy docs say `biufcmMOSUV` only)

```python
for letter in string.ascii_letters:
    try:
        print(letter, np.dtype(letter))
    except TypeError as exc:
        pass
```

 - [x] Closes #1952
 - [x] Tests added (for all bug fixes or enhancements)
 - [x] Tests passed (for all non-documentation changes)
 - [ ] Fully documented, including `whats-new.rst` for all changes and `api.rst` for new API (remove if this change should not be visible to users, e.g., if it is an internal clean-up, or if this is part of a larger project that will be documented later)
",2018-03-02T18:11:49Z,2018-08-20T16:35:50Z,2018-08-20T16:31:16Z,2018-08-20T16:31:15Z,69086b332c6c950587830b266df4e624c2106d89,,,0,07d0fd393d0830acdc629274aa7fb35e96390ff8,0b9ab2d12ae866a27050724d94facae6e56f5927,CONTRIBUTOR,,13221727,https://github.com/pydata/xarray/pull/1953,