I launched Qt Creator with no project open, and it's raising two issues:

error: Project ERROR: You need to set the ANDROID_NDK_ROOT environment variable to point to your Android NDK.

error: Could not read qmake configuration file /Users/gavin/Qt/5.15.2/android/mkspecs/android-clang/qmake.conf.

But ANDROID_NDK_ROOT is set up in zshenv, and works at the command line:

% echo $ANDROID_NDK_ROOT

/Users/gavin/Library/Android/sdk/ndk/21.1.6352462

I've also tried exporting a path that ends at ndk/ (without the specific version subdirectory). No dice either. And that qmake.conf file exists at the above-cited path.

I also verified that Qt Creator has full disk access permission. Don't know what else to check.