### Please describe the problem.

I am establishing running daily tests on annex on NFS mounted partition (one run with NFS as TMPDIR -- passes, another with NFS for HOME).

### What version of git-annex are you using? On what operating system?

as of now  git-annex-standalone_8.20200810+git47-g27329f0bb-1~ndall+1_amd64.deb 

### Please provide any additional information below.

[full build/log](https://github.com/datalad/datalad-extensions/pull/29/checks?check_run_id=1024502537)

[[!format sh """
...
All 840 tests passed (707.87s)
.t/gpgtmp/7: removePathForcibly:removePathForcibly:removePathForcibly:removeDirectory: unsatisfied constraints (Directory not empty)
sleeping 10 seconds and will retry directory cleanup
git-annex: .t/gpgtmp/7/.nfs0000000000669ff400000a6b: removePathForcibly:removePathForcibly:removePathForcibly:removePathForcibly:removeLink: resource busy (Device or resource busy)
##[error]Process completed with exit code 1.
"""]]

so it seems to relate to gpg, and not unlikely to be out of git-annex control, but I wondered if it could potentially be some non-clean termination of underlying gpg process or alike which could/should actually be addressed on git-annex side?

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

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