File Locking with Resource Compiler. Why?

[A.v.O]

Why does the resource compiler lock files?

My Setup

I have:

• Linux Kubuntu 20.04 LTS
• NFS mount to my sources
• CMake project file
• CLion

Problem

For some reason when building a Qt demo project I get file locking failures.

Excerpt 'CMakeLists.txt'

set(CMAKE_AUTOUIC ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)

set(SOURCES
	main.cpp
	mainwindow.cpp
	mainwindow.h
	myform.ui
	demo1.qrc
	)

AutoRcc error
-------------
Locking of the lock file "SRC:/cmake-build-debug/CMakeFiles/demo1_autogen.dir/AutoRcc_demo1_EWIEGA46WW_Lock.lock" failed.
No locks available

When setting up the CMakeLists.txt as presented next there is no problem.

set(SOURCES
	main.cpp
	mainwindow.cpp
	mainwindow.h
	myform.ui
	)

qt5_add_resources(SOURCES demo1.qrc)

Enabling file locking on my Linux server with systemctl enable rpc-statd and systemctl start rpc-statd also fixed the problem for me since there is no qt6_add_resources(...) function anymore.

Questions

File locking is possible on NFS but for other types of mounts it is not.
Is there a possibility to disable file locking?
Why is there a need for file locking anyway?

[Christian Ehrlicher]

I don't see what Qt can do against this - when the OS says that there are no resources available (No locks available) the app can't do anything against it.

[A.v.O]

@Christian-Ehrlicher said in File Locking with Resource Compiler. Why?:

I don't see what Qt can do against this - when the OS says that there are no resources available (No locks available) the app can't do anything against it.

It is Qt's resource compiler that is doing the locking.