<![CDATA[QtCreator 20 defaulting to Unix makefilesfor cmake on Ubuntu]]>Using a clean installation of Ubuntu, I installed latest Qt and used QtCreator to open my cmake project. I see that it defaults to the CMAKE_GENERATOR being Unix Makefiles, so is only building the project on one core. So how do I switch it to using Ninja? There seems to be three places to change. First is the "Kit Configuration" dialog. I can set Ninja there, but it seems to make no difference. Then there is the Initial Configuration and Current Configuration tabs. Editing the fields CMAKE_GENERATOTR in both those tabs, causes the entry to go red in color, but when I run cmake, they get changed back to Unix makefiles.

This is the second new machine I have had this problem on. On the first I somehow after going round and round in circles, I managed to put /home/david/Qt/Tools/Ninja/ninja into the CMAKE_GEBERATOR field and have it stick there. It remains red in color, but the builds work. But on this second machine using trial and error I still cant make it stick, it always reverts to Unix makefiles even though Ninja is selected in Kit Configuration. Help would be appreciated.

]]>https://forum.qt.io/topic/164876/qtcreator-20-defaulting-to-unix-makefilesfor-cmake-on-ubuntuRSS for NodeMon, 31 Aug 2026 20:31:18 GMTSun, 12 Jul 2026 00:21:18 GMT60<![CDATA[Reply to QtCreator 20 defaulting to Unix makefilesfor cmake on Ubuntu on Mon, 13 Jul 2026 14:31:42 GMT]]>@ChortleMortal This usually happens when you don't have ninja in PATH.

macOS with homebrew has this issue too.

My fix was to go to Preferences > Devices > Local PC and add /opt/homebrew/bin to the

Search in directories
field.

macos-ninja.png

The other option is to set the CMAKE_MAKE_PROGRAM CMake variable to your /path/to/ninja executable, whilst having CMAKE_GENERATOR set to Ninja.

]]>https://forum.qt.io/post/839140https://forum.qt.io/post/839140Mon, 13 Jul 2026 14:31:42 GMT<![CDATA[Reply to QtCreator 20 defaulting to Unix makefilesfor cmake on Ubuntu on Mon, 13 Jul 2026 18:09:14 GMT]]>And if you have Ninja installed via Qt SDK, you should have in your QtCreator.ini something like:

[CMakeSpecificSettings]
NinjaPath=/Users/cristian/Qt/Tools/Ninja//ninja

which should get CMAKE_MAKE_PROGRAM set to this value.

]]>https://forum.qt.io/post/839143https://forum.qt.io/post/839143Mon, 13 Jul 2026 18:09:14 GMT<![CDATA[Reply to QtCreator 20 defaulting to Unix makefilesfor cmake on Ubuntu on Mon, 13 Jul 2026 17:29:43 GMT]]>@cristian-adam
Thank you so much, Both your solutions work. Your posting t not only solves the problem for me but adds clarity as to what is happening.

I set both CMAKE_GENERATOR and CMAKE_MAKE_PROGRAM and now cmake is running and building on all cores.

After this I looked at the Devices tab in preferences and saw the relationship of the programs qtcreator uses and PATH. Coming from the windows environment I had never looked at this preference page before. All my entries were empty, meaning it used $PATH. qtinstaller puts ninja in Qt/Tools/Ninja but presumably does nothing to the path. So I set the path to ninja in the Devices page, then created a new session and used another repository, and this time it defaulted to Ninja, and of course worked perfectly

Once again thanks,
David

]]>https://forum.qt.io/post/839142https://forum.qt.io/post/839142Mon, 13 Jul 2026 17:29:43 GMT<![CDATA[Reply to QtCreator 20 defaulting to Unix makefilesfor cmake on Ubuntu on Mon, 13 Jul 2026 14:31:42 GMT]]>@ChortleMortal This usually happens when you don't have ninja in PATH.

macOS with homebrew has this issue too.

My fix was to go to Preferences > Devices > Local PC and add /opt/homebrew/bin to the

Search in directories
field.

macos-ninja.png

The other option is to set the CMAKE_MAKE_PROGRAM CMake variable to your /path/to/ninja executable, whilst having CMAKE_GENERATOR set to Ninja.

]]>https://forum.qt.io/post/839140https://forum.qt.io/post/839140Mon, 13 Jul 2026 14:31:42 GMT