Qmake variable seems to be empty after assigning a variable to it in a !defined condition

[devjb]

Hi,

I used to have the following block in my pro file

QT_REQUIREDVERSION_MAJOR=5
QT_REQUIREDVERSION_MINOR=12
QT_REQUIREDVERSION_PATCH=7

#version check qt
!equals(QT_VERSION, "$${QT_REQUIREDVERSION_MAJOR}.$${QT_REQUIREDVERSION_MINOR}.$${QT_REQUIREDVERSION_PATCH}") {
message("Cannot build with Qt version $${QT_VERSION}.")
error("Use specific Qt version: $${QT_REQUIREDVERSION_MAJOR}.$${QT_REQUIREDVERSION_MINOR}.$${QT_REQUIREDVERSION_PATCH}.")
}

To gain flexibility to pass variables during the qmake call, I changed this to be:

message(Defining required qt version variables)
!defined(QT_REQUIREDVERSION_MAJOR){
	QT_REQUIREDVERSION_MAJOR=5
	message("Required Qt major version QT_REQUIREDVERSION_MAJOR has not been given, defaulting to $${QT_REQUIREDVERSION_MAJOR}")
}
!defined(QT_REQUIREDVERSION_MINOR){
	QT_REQUIREDVERSION_MINOR=12
	message("Required Qt minor version QT_REQUIREDVERSION_MINOR has not been given, defaulting to $${QT_REQUIREDVERSION_MINOR}")
}
!defined(QT_REQUIREDVERSION_PATCH){
	QT_REQUIREDVERSION_PATCH=7
	message("Required Qt patch version QT_REQUIREDVERSION_PATCH has not been given, defaulting to $${QT_REQUIREDVERSION_PATCH}")
}

#version check qt
!equals(QT_VERSION, "$${QT_REQUIREDVERSION_MAJOR}.$${QT_REQUIREDVERSION_MINOR}.$${QT_REQUIREDVERSION_PATCH}") {
	message("Cannot build with Qt version $${QT_VERSION}.")
	error("Use specific Qt version: $${QT_REQUIREDVERSION_MAJOR}.$${QT_REQUIREDVERSION_MINOR}.$${QT_REQUIREDVERSION_PATCH}.")
}

With the result, that the variables are empty in the !equals() condition, but are correctly printed during the !defined() condition.
How can I fix this? What am I doing wrong here?

[devjb]

Now I am absolutely confused. It is working. Maybe some Qt creator fuckup, I tested it on a different qt version in docker, where it worked, came back to qt creator, where it still did not, restarted qt creator and it worked....

Sometimes qmake drives me crazy.

[sierdzio]

Here is output I get with your code:

Project MESSAGE: Required Qt major version QT_REQUIREDVERSION_MAJOR has not been given, defaulting to 5
Project MESSAGE: Required Qt minor version QT_REQUIREDVERSION_MINOR has not been given, defaulting to 12
Project MESSAGE: Required Qt patch version QT_REQUIREDVERSION_PATCH has not been given, defaulting to 7
Project MESSAGE: Cannot build with Qt version 5.15.1.
Project ERROR: Use specific Qt version: 5.12.7.

When I change Qt version to match, it also works as expected.

What am I doing wrong here?

Nothing, apparently. Your code, as posted, is correct.

Maybe the code you have in .pro is slightly different (typos?) or gets executed in different order?

[devjb]

Weird.

My Output with the exact same code:

Project MESSAGE: Defining required qt version variables
Project MESSAGE: Required Qt major version QT_REQUIREDVERSION_MAJOR has not been given, defaulting to 5
Project MESSAGE: Required Qt minor version QT_REQUIREDVERSION_MINOR has not been given, defaulting to 12
Project MESSAGE: Required Qt patch version QT_REQUIREDVERSION_PATCH has not been given, defaulting to 7
Project MESSAGE: Cannot build with Qt version 5.12.7.
Project ERROR: Use specific Qt version: ...

[J.Hilk]

@devjb do you have a qmake.conf file inside your project folder (or the parent folders!) that may interfere?

[sierdzio]

Try running with different Qt version... maybe there is some bug in qmake in the release you are using?

Check your code, maybe you are replacing the values somewhere else?

[devjb]

I try to reproduce the behaviour with a minimal example. I think the issue has to do with including that snippet in multiple pro files of my sub project. I hoped that I can achieve proper variable propagation top down in the nested projects, which apparently does not work correctly :-(

When I have one single qmake file where I use the snippet, it seems to work.

[devjb]

In an empty project, I put a minimal example together:

include(commonvariables.pri)

#version check qt
!equals(QT_VERSION, "$${QT_REQUIREDVERSION_MAJOR}.$${QT_REQUIREDVERSION_MINOR}.$${QT_REQUIREDVERSION_PATCH}") {
	message("Cannot build with Qt version $${QT_VERSION}.")
	error("Use specific Qt version: $${QT_REQUIREDVERSION_MAJOR}.$${QT_REQUIREDVERSION_MINOR}.$${QT_REQUIREDVERSION_PATCH}.")
}
message("Building allowed with Qt version $${QT_VERSION}")

where commonvariables.pri is

# variables for a whole build

# define the required qt version to build the project
message(Defining required qt version variables)
!defined(QT_REQUIREDVERSION_MAJOR){
	QT_REQUIREDVERSION_MAJOR=5
	message("Required Qt major version QT_REQUIREDVERSION_MAJOR has not been given, defaulting to $${QT_REQUIREDVERSION_MAJOR}")
}
!defined(QT_REQUIREDVERSION_MINOR){
	QT_REQUIREDVERSION_MINOR=12
	message("Required Qt minor version QT_REQUIREDVERSION_MINOR has not been given, defaulting to $${QT_REQUIREDVERSION_MINOR}")
}
!defined(QT_REQUIREDVERSION_PATCH){
	QT_REQUIREDVERSION_PATCH=7
	message("Required Qt patch version QT_REQUIREDVERSION_PATCH has not been given, defaulting to $${QT_REQUIREDVERSION_PATCH}")
}

when i put the contents of commonvariable.pri in place, it works. I wonder why such an include of variables works in other places, where I alter for example LIBS or QT variables in .pri files but not here.

[devjb]

Now I am absolutely confused. It is working. Maybe some Qt creator fuckup, I tested it on a different qt version in docker, where it worked, came back to qt creator, where it still did not, restarted qt creator and it worked....

Sometimes qmake drives me crazy.