diff -up qwt-6.1.5/qwtbuild.pri.qt_install_paths qwt-6.1.5/qwtbuild.pri
--- qwt-6.1.5/qwtbuild.pri.qt_install_paths	2020-07-13 13:22:57.829775189 -0500
+++ qwt-6.1.5/qwtbuild.pri	2020-07-13 13:23:39.719159410 -0500
@@ -14,7 +14,7 @@
 CONFIG           += qt
 CONFIG           += warn_on
 CONFIG           += no_keywords
-CONFIG           += silent
+#CONFIG           += silent
 
 DEFINES += QT_NO_DEPRECATED_WARNINGS # not fixing those before Qwt 6.2
 
diff -up qwt-6.1.5/qwtconfig.pri.qt_install_paths qwt-6.1.5/qwtconfig.pri
--- qwt-6.1.5/qwtconfig.pri.qt_install_paths	2020-06-01 11:48:07.325112226 -0500
+++ qwt-6.1.5/qwtconfig.pri	2020-07-13 13:22:57.831775207 -0500
@@ -19,7 +19,7 @@ QWT_VERSION      = $${QWT_VER_MAJ}.$${QW
 QWT_INSTALL_PREFIX = $$[QT_INSTALL_PREFIX]
 
 unix {
-    QWT_INSTALL_PREFIX    = /usr/local/qwt-$$QWT_VERSION
+    # QWT_INSTALL_PREFIX    = /usr/local/qwt-$$QWT_VERSION
     # QWT_INSTALL_PREFIX = /usr/local/qwt-$$QWT_VERSION-qt-$$QT_VERSION
 }
 
@@ -28,9 +28,9 @@ win32 {
     # QWT_INSTALL_PREFIX = C:/Qwt-$$QWT_VERSION-qt-$$QT_VERSION
 }
 
-QWT_INSTALL_DOCS      = $${QWT_INSTALL_PREFIX}/doc
-QWT_INSTALL_HEADERS   = $${QWT_INSTALL_PREFIX}/include
-QWT_INSTALL_LIBS      = $${QWT_INSTALL_PREFIX}/lib
+QWT_INSTALL_DOCS      = $$[QT_INSTALL_DOCS]/html
+QWT_INSTALL_HEADERS   = $$[QT_INSTALL_HEADERS]/qwt
+QWT_INSTALL_LIBS      = $$[QT_INSTALL_LIBS]
 
 ######################################################################
 # Designer plugin
@@ -42,7 +42,8 @@ QWT_INSTALL_LIBS      = $${QWT_INSTALL_P
 # runtime environment of designer/creator.
 ######################################################################
 
-QWT_INSTALL_PLUGINS   = $${QWT_INSTALL_PREFIX}/plugins/designer
+#QWT_INSTALL_PLUGINS   = $${QWT_INSTALL_PREFIX}/plugins/designer
+QWT_INSTALL_PLUGINS   = $$[QT_INSTALL_PLUGINS]/designer
 
 # linux distributors often organize the Qt installation
 # their way and QT_INSTALL_PREFIX doesn't offer a good
@@ -63,8 +64,8 @@ QWT_INSTALL_PLUGINS   = $${QWT_INSTALL_P
 # with every Qt upgrade.
 ######################################################################
 
-QWT_INSTALL_FEATURES  = $${QWT_INSTALL_PREFIX}/features
-# QWT_INSTALL_FEATURES  = $$[QT_INSTALL_PREFIX]/features
+#QWT_INSTALL_FEATURES  = $${QWT_INSTALL_PREFIX}/features
+QWT_INSTALL_FEATURES  = $$[QMAKE_MKSPECS]/features
 
 ######################################################################
 # Build the static/shared libraries.
@@ -110,7 +111,7 @@ QWT_CONFIG     += QwtOpenGL
 # to your qmake project file.
 ######################################################################
 
-#QWT_CONFIG     += QwtMathML
+QWT_CONFIG     += QwtMathML
 
 ######################################################################
 # If you want to build the Qwt designer plugin,