actually, deploy the qt.conf separately

QGCPostLinkCommon.pri

@@ -165,4 +165,7 @@ LinuxBuild {
     }
 
     QMAKE_POST_LINK += && QTDIR="$$DESTDIR/Qt" RPATHDIR="$$DESTDIR/Qt/libs" QTCONF_PATH="$$DESTDIR/qt.conf" $$SOURCE_DIR/deploy/linux-post-link.sh
+
+    # https://doc.qt.io/qt-5/qt-conf.html
+    QMAKE_POST_LINK += && cp deploy/qt.conf $$DESTDIR
 }

deploy/linux-post-link.sh

@@ -23,13 +23,6 @@
 # to be used, like such:
 # LD_LIBRARY_PATH=./Qt/libs ./QGroundControl
 #
-# In addition, Qt will sometimes want to reference its own directory to find
-# certain resources. This installs a file, qt.conf, which tells Qt where its
-# installation is at.
-# Without the qt.conf file, you would need to tell Qt where to find certain
-# files, particularly for QML, like such:
-# QML2_IMPORT_PATH=./Qt/qml QT_PLUGIN_PATH=./Qt/plugins ./QGroundControl
-#
 
 # -e: stop on error
 # -u: undefined variable use is an error
@@ -92,11 +85,3 @@ while IFS='' read -r library; do
     # patch the library's rpath
     patchelf --set-rpath "${new_rpath}" "${library}"
 done
-
-# Create a qt.conf file
-# https://doc.qt.io/qt-5/qt-conf.html
-cat <<EOF > "${QTCONF_PATH}"
-[Paths]
-Prefix=./Qt
-Libraries=libs
-EOF

deploy/qt.conf

@@ -0,0 +1,3 @@
+[Paths]
+Prefix=./Qt
+Libraries=libs