lupdate misses strings when called with absolute path
I am witnessing a really weird behaviour regarding the direct call of lupdate :
When I call
lupdate C:\project\source -ts result_fr.ts
I get :
Updating 'result_fr.ts'... Found 56 source text(s) (14 new and 42 already existing)
but if I call it to scan the local directory, which is C:\project\source\ :
lupdate . -ts result_fr.ts
I get :
Updating 'result_fr.ts'... Found 42 source text(s) (0 new and 42 already existing) Kept 14 obsolete entries
So it seems that the outcome of lupdate is dependant on the using of absolute/relative path. An interesting detail is that the 14 entries difference are only QT_TRANSLATE_NOOP calls. Does anybody have an idea of what's happening here ?
I am using Qt 5.6.0.