malloc_trim is not available on musl and it isn't needed anyway.
--- qt-creator-opensource-src-4.15.2/src/app/main.cpp.old	2021-07-12 21:12:53.000000000 -0500
+++ qt-creator-opensource-src-4.15.2/src/app/main.cpp	2022-11-22 00:29:21.110626363 -0600
@@ -782,7 +782,7 @@
     // shutdown plugin manager on the exit
     QObject::connect(&app, &QCoreApplication::aboutToQuit, &pluginManager, &PluginManager::shutdown);
 
-#ifdef Q_OS_LINUX
+#if defined(Q_OS_LINUX) && defined(__GLIBC__)
     class MemoryTrimmer : public QObject
     {
     public: