[OE-core][PATCH v2] wic/engine: warn about old host debugfs for standalone directory copy

Daniel Dragomir
2026-01-09T17:45:51Z

When wic is used in standalone mode, it relies on host tools such as
debugfs. For directory host->image copies into ext* partitions, wic
uses scripted debugfs "-f" input with multiple mkdir/write commands.

Older host debugfs versions (< 1.46.5) may behave unreliably in this
mode and can silently miss files. This does not affect builds using
debugfs from OE where the version is known to be sufficiently new.

Add a debugfs version check and emit a warning when an older host
debugfs is detected. The warning is shown once per run and does not
alter execution.

Changes in v2:
- adjust the last working debugfs version to 1.46.5

Signed-off-by: Daniel Dragomir <daniel.dragomir@windriver.com>
---
scripts/lib/wic/engine.py | 37 +++++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)

diff --git a/scripts/lib/wic/engine.py b/scripts/lib/wic/engine.py
index 9d596be3a7..40be6f908a 100644
--- a/scripts/lib/wic/engine.py
+++ b/scripts/lib/wic/engine.py
@@ -222,6 +222,42 @@ def wic_list(args, scripts_path):

return False

+_DEBUGFS_VERSION = None
+_DEBUGFS_WARNED = False
+
+def debugfs_version_check(debugfs_path, min_ver=(1, 46, 5)):
+ global _DEBUGFS_VERSION, _DEBUGFS_WARNED
+
+ if _DEBUGFS_WARNED:
+ return
+
+ # Detect version once
+ if _DEBUGFS_VERSION is None:
+ out = ""
+ for flag in ("-V", "-v"):
+ try:
+ out = exec_cmd(f"{debugfs_path} {flag}")
+ break
+ except Exception:
+ continue
+
+ import re
+ m = re.search(r"(\d+)\.(\d+)\.(\d+)", out or "")
+ _DEBUGFS_VERSION = tuple(map(int, m.groups())) if m else None
+
+ ver = _DEBUGFS_VERSION
+
+ # Compare and warn once
+ if ver is not None and ver < min_ver:
+ logger.warning(
+ "debugfs %s detected (< 1.46.5): Directory copies into ext* partitions "
+ "via scripted debugfs (-f) may be unreliable. Consider using a newer "
+ "debugfs, for example via a native sysroot from a newer SDK.",
+ ".".join(map(str, ver)) if ver else "unknown"
+ )
+
+ _DEBUGFS_WARNED = True
+

class Disk:
def __init__(self, imagepath, native_sysroot, fstypes=('fat', 'ext')):
@@ -352,6 +388,7 @@ class Disk:
if self.partitions[pnum].fstype.startswith('ext'):
if isinstance(src, str): # host to image case
if os.path.isdir(src):
+ debugfs_version_check(self.debugfs)
base = os.path.abspath(src)
base_parent = os.path.dirname(base)
cmds = []
--
2.25.1