Fix findQmlImportScanner() on FreeBSD

We don't install the qmlimportscanner executable into public location, so add
a bit of extra logic to locate it.

Author: arrowd

src/qml.cpp

@@ -1,6 +1,10 @@
 // system headers
 #include <filesystem>
 
+#ifdef __FreeBSD__
+#include <sys/sysctl.h>
+#endif
+
 // library includes
 #include <nlohmann/json.hpp>
 #include <linuxdeploy/core/appdir.h>
@@ -22,7 +26,20 @@ using namespace nlohmann;
 namespace fs = std::filesystem;
 
 fs::path findQmlImportScanner() {
-    return which("qmlimportscanner");
+    auto path = which("qmlimportscanner");
+#ifdef __FreeBSD__
+    int mib[2];
+    char buf[PATH_MAX];
+    size_t len = PATH_MAX;
+
+    mib[0] = CTL_USER;
+    mib[1] = USER_LOCALBASE;
+    if (::sysctl(mib, 2, buf, &len, NULL, 0) != 0)
+        return path;
+
+    path = which(std::string(buf) + "/libexec/qt6/qmlimportscanner");
+#endif
+    return path;
 }
 
 std::string runQmlImportScanner(const std::vector<std::filesystem::path> &sourcesPaths, const std::vector<fs::path> &qmlImportPaths) {