### Please describe the problem.

Recently, with 8.20201129+git100-g2d84bf992 version of git-annex and whatever states of datalad, we have celebrated a Windows Green Day -- our CI was totally green for Windows.

But then Windows started to fail again.  Currently (8.20201129+git125-g7f72314bf) due to

```
2021-01-18T14:42:32.7075079Z     prop_relPathDirToFileAbs_basics:                      FAIL
2021-01-18T14:42:32.7078493Z       *** Failed! Falsified (after 54 tests):
2021-01-18T14:42:32.7082732Z       TestableFilePath {fromTestableFilePath = "/*LFy?\ETBoj(96"}
2021-01-18T14:42:32.7084569Z       Use --quickcheck-replay=725893 to reproduce.
```

full list of recent runs with logs etc: [datalad/git-annex github actions](https://github.com/datalad/git-annex/actions?query=workflow%3A%22Build+git-annex+on+Windows%22).  Note that `git annex version` reported is "off": [just filed an issue](https://github.com/datalad/git-annex/issues/44)

[[!meta author=yoh]]
[[!tag projects/datalad]]

> [[fixed|done]] --[[Joey]]
