Re: [PULL 14/17] iotests: test O_TRUNC behavior for fuse exports

Hi Kevin and Fiona,
Please take a look at the following CI failure and send a new pull request:

https://gitlab.com/qemu-project/qemu/-/jobs/15583116603#L174

88/104 block-raw-optional+block-slow - qemu:io-raw-fuse-truncate ERROR
0.24s exit status 1
>>> MESON_TEST_ITERATION=1 MSAN_OPTIONS=halt_on_error=1:abort_on_error=1:print_summary=1:print_stacktrace=1 RUST_BACKTRACE=1 ASAN_OPTIONS=halt_on_error=1:abort_on_error=1:print_summary=1 MALLOC_PERTURB_=106 UBSAN_OPTIONS=halt_on_error=1:abort_on_error=1:print_summary=1:print_stacktrace=1 LD_LIBRARY_PATH=/builds/qemu-project/qemu/build/subprojects/libvfio-user/lib PYTHON=/builds/qemu-project/qemu/build/pyvenv/bin/python3 /builds/qemu-project/qemu/build/pyvenv/bin/python3 /builds/qemu-project/qemu/build/../tests/qemu-iotests/check -tap -raw fuse-truncate --source-dir /builds/qemu-project/qemu/tests/qemu-iotests --build-dir /builds/qemu-project/qemu/build/tests/qemu-iotests
――――――――――――――――――――――――――――――――――――― ✀ ―――――――――――――――――――――――――――――――――――――
stderr:
--- /builds/qemu-project/qemu/tests/qemu-iotests/tests/fuse-truncate.out
+++ /builds/qemu-project/qemu/build/scratch/raw-file-fuse-truncate/fuse-truncate.out.bad
@@ -1,5 +1,23 @@
-...
+E..
+======================================================================
+ERROR: test_o_trunc (__main__.TestTruncateBlockdev)
+----------------------------------------------------------------------
+Traceback (most recent call last):
+ File "/builds/qemu-project/qemu/tests/qemu-iotests/tests/fuse-truncate",
line 93, in setUp
+ self.evaluate_preconditions()
+ File "/builds/qemu-project/qemu/tests/qemu-iotests/tests/fuse-truncate",
line 133, in evaluate_preconditions
+ self.supports_preconditions = check_sudo_support()
+ File "/builds/qemu-project/qemu/tests/qemu-iotests/tests/fuse-truncate",
line 41, in check_sudo_support
+ subprocess.run(['sudo', '-n', 'losetup', '--version'],
+ File "/usr/lib64/python3.9/subprocess.py", line 505, in run
+ with Popen(*popenargs, **kwargs) as process:
+ File "/usr/lib64/python3.9/subprocess.py", line 951, in __init__
+ self._execute_child(args, executable, preexec_fn, close_fds,
+ File "/usr/lib64/python3.9/subprocess.py", line 1837, in _execute_child
+ raise child_exception_type(errno_num, err_msg, err_filename)
+FileNotFoundError: [Errno 2] No such file or directory: 'sudo'