<![CDATA[Qt Creator not picking up changes to .cpp files, will not build unless I first clean the project?]]>Using Qt Creator 19.0.0 on Linux Ubuntu 24.04 (gcc_64) from revision 99d590c8c9:

I was used to making little changes in a source file and then right-clicking the single file in the "Project" view, then choose "Build" from the context menu which should register that the file had changed and then re-compile the selected source file.

Now, when I do the same, and after I save the file, I get this in the "Compile" output (for example, I want to compile "MySource.cpp"):

make: Nothing to be done for '.obj/MySource.o'

It isn't picking up the changes I just made.

I consider this to be a bug ... does anyone have a workaround, or knows about a setting in "Preferences" which I can set to revert to the old behavior?

(EDIT: In my qmake project file, I have set a custom OBJECTS_DIR which is why there is a subfolder .obj/ in the compiler output)

]]>https://forum.qt.io/topic/164573/qt-creator-not-picking-up-changes-to-.cpp-files-will-not-build-unless-i-first-clean-the-projectRSS for NodeTue, 28 Apr 2026 17:21:29 GMTFri, 17 Apr 2026 10:41:51 GMT60<![CDATA[Reply to Qt Creator not picking up changes to .cpp files, will not build unless I first clean the project? on Fri, 17 Apr 2026 13:06:34 GMT]]>The plot thickens...

I cleaned out the entire build directory, including what I thought might have been a stale .qmake.stash file. After building everything successfully from scratch, I introduced an error by intentionally misspelling one of the variables in a function in MySource.cpp. Tried to compile that single file and got the same error as reported above.

So I corrected the error, right-clicked once more on the file name in the "Projects" view, and now I have this error:

:-1: error: No rule to make target '.obj/MySource.o'.  Stop.

Once again, I click on the main "Build" icon on the bottom left, and everything successfully compiles and links. I tried to make a minimal project to reproduce the error, but I cannot pin it down. It doesn't seem to have anything to do with the presence of the OBJECTS_DIR variable. It could be that the source file is in a subproject of the main project which has TEMPLATE=subdirs. But the subproject is TEMPLATE=app. And this did work for many years (i.e. compiling a single file from the "Projects" view context menu). Something has broken recently.

]]>https://forum.qt.io/post/837818https://forum.qt.io/post/837818Fri, 17 Apr 2026 13:06:34 GMT