The modifications in this commit allows the unit tests
to run on both, pytest 6.x (nose test layout) and the new
pytest 7.x (xunit test layout). This Fixes#2072 in a
much nicer way. Thanks much to @smarlowucf
A speciality of the rsync tool is that it behaves differently
if the given source_dir ends with a '/' or not. If it ends
with a slash the data structure below will be synced to the
target_dir. If it does not end with a slash the source_dir
and its contents are synced to the target_dir. For example:
source
└── some_data
1. $ rsync -a source target
target
└── source
└── some_data
2. $ rsync -a source/ target
target
└── some_data
The parameter force_trailing_slash in the DataSync::sync_data
method can be used to make sure rsync behaves like shown in
the second case. This Fixes#1786
