issue37 test problems

[ewxrjk]

Description

* ==== ./issue37 ====
1+0 records in
1+0 records out
4096 bytes (4.1 kB, 4.0 KiB) copied, 0.000362246 s, 11.3 MB/s
2048+0 records in
2048+0 records out
2097152 bytes (2.1 MB, 2.0 MiB) copied, 0.0167765 s, 125 MB/s
[Errno 95] Operation not supported: b'/var/lib/build/_builds/heceptor/rsbackup/tests/w-issue37/volume1/has_xattr'
FAIL issue37 (exit status: 1)

Environment

• Works on Debian bullseye userland
• Fails on sid userland, with build/test on a tmpfs, in a docker container, over bullseye kernel.

Analysis

It's not known why this fails.

• xattr -w works fine on a tmpfs in the host (bullseye userland)
• xattr -w works fine on ext4 in the sid container
• xattr -w does not work on a tmpfs in the sid container

i.e. it is the combination of tmpfs+container that breaks.

The current behaviour is to skip the test if xattr -w fails (see e90cdfb8fc7127bd99e85ce9b72578e66e46e9cb).