Bug#941547: glib2.0: intermittent test failure: gio/tests/g-file-info.c:190:test_g_file_info_modification_time: assertion failed (ts == 0): (-1 == 0)

[Simon McVittie]

Source: glib2.0
Version: 2.62.0-2
Severity: important

glib2.0 intermittently fails one of its tests. I've observed this on the
buildds, and during autopkgtest in a VM on my laptop.

This might be i386-specific - I haven't observed it on other
architectures.

> 1..2
> # Start of g-file-info tests
> ok 1 /g-file-info/test_g_file_info
> # Start of test_g_file_info tests
> # /g-file-info/test_g_file_info/modification-time summary: Test that getting the modification time of a file works.
> # GLib-GIO-DEBUG: _g_io_module_get_default: Found default implementation local (GLocalVfs) for ?gio-vfs?
> **
> GLib-GIO:ERROR:../../../gio/tests/g-file-info.c:190:test_g_file_info_modification_time: assertion failed (ts == 0): (-1 == 0)
> Bail out! GLib-GIO:ERROR:../../../gio/tests/g-file-info.c:190:test_g_file_info_modification_time: assertion failed (ts == 0): (-1 == 0)

The test in question asserts that we can:

* read the modification time of a file, with microsecond precision
* set a modification time 50 microseconds later
* read the modification time back
* get the same modification time we set

and the failure mode is that the file's new mtime is 1 microsecond older
than what we asked for.

I think my test VM is using ext4 for all filesystems, if that matters.

-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'stable-debug'), (500, 'buildd-unstable'), (500, 'unstable'), (500, 'testing'), (500, 'stable'), (500, 'oldstable'), (1, 'experimental-debug'), (1, 'buildd-experimental'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.2.0-3-amd64 (SMP w/2 CPU cores)
Kernel taint flags: TAINT_WARN, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_GB.utf8, LC_CTYPE=en_GB.utf8 (charmap=UTF-8), LANGUAGE=en_GB:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled