~/src2/qwt-6.1 > cat qwt_diff_r2055_r2048.log
Index: playground/playground.pri
===================================================================
--- playground/playground.pri   (revision 2048)
+++ playground/playground.pri   (working copy)
@@ -36,18 +36,8 @@


 QMAKE_RPATHDIR *= $${QWT_ROOT}/lib
+qwtAddLibrary($${QWT_OUT_ROOT}/lib, qwt)

-contains(QWT_CONFIG, QwtFramework) {
-
-    LIBS      += -F$${QWT_OUT_ROOT}/lib
-}
-else {
-
-    LIBS      += -L$${QWT_OUT_ROOT}/lib
-}
-
-qwtAddLibrary(qwt)
-
 greaterThan(QT_MAJOR_VERSION, 4) {

     QT += printsupport
Index: qwtbuild.pri
===================================================================
--- qwtbuild.pri        (revision 2048)
+++ qwtbuild.pri        (working copy)
@@ -70,17 +70,3 @@
     # are built in the release and debug subdirectories
     OBJECTS_DIR       = obj
 }
-
-unix {
-
-    exists( $${QMAKE_LIBDIR_QT}/libqwt.* ) {
-
-        # On some Linux distributions the Qwt libraries are installed
-        # in the same directory as the Qt libraries. Unfortunately
-        # qmake always adds QMAKE_LIBDIR_QT at the beginning of the
-        # linker path, so that the installed libraries will be
-        # used instead of the local ones.
-
-        error( "local build will conflict with $${QMAKE_LIBDIR_QT}/libqwt.*" )
-    }
-}
Index: textengines/mathml/qwtmathml.prf
===================================================================
--- textengines/mathml/qwtmathml.prf    (revision 2048)
+++ textengines/mathml/qwtmathml.prf    (working copy)
@@ -8,6 +8,7 @@
 ################################################################

 include ( ./qwtconfig.pri )
+include ( ./qwtfunctions.pri )

 contains(QWT_CONFIG, QwtDll) {

@@ -19,20 +20,10 @@
 contains(QWT_CONFIG, QwtFramework) {

     INCLUDEPATH *= $${QWT_INSTALL_LIBS}/qwtmathml.framework/Headers
-    LIBS        *= -F$${QWT_INSTALL_LIBS}
 }
 else {

     INCLUDEPATH *= $${QWT_INSTALL_HEADERS}
-    LIBS        *= -L$${QWT_INSTALL_LIBS}
 }

-INCLUDEPATH_QWTMATHML = $${INCLUDEPATH}
-qtAddLibrary(qwtmathml)
-
-# we don't want qtAddLibrary to expand the
-# include path, with directories, that might
-# conflict with other installations of qwt
-
-INCLUDEPATH      = $${INCLUDEPATH_QWTMATHML}
-
+qwtAddLibrary($${QWT_INSTALL_LIBS}, qwtmathml)
Index: textengines/textengines.pri
===================================================================
--- textengines/textengines.pri (revision 2048)
+++ textengines/textengines.pri (working copy)
@@ -32,15 +32,10 @@
 contains(QWT_CONFIG, QwtFramework) {

     CONFIG += lib_bundle
-    LIBS      += -F$${QWT_OUT_ROOT}/lib
 }
-else {

-    LIBS      += -L$${QWT_OUT_ROOT}/lib
-}
+qwtAddLibrary($${QWT_OUT_ROOT}, qwt)

-qwtAddLibrary(qwt)
-
 # Install directives

 target.path    = $${QWT_INSTALL_LIBS}
Index: qwtfunctions.pri
===================================================================
--- qwtfunctions.pri    (revision 2048)
+++ qwtfunctions.pri    (working copy)
@@ -35,8 +35,30 @@

 defineTest(qwtAddLibrary) {

-    LIB_NAME = $$1
+    LIB_PATH = $$1
+    LIB_NAME = $$2

+       mac:contains(QWT_CONFIG, QwtFramework) {
+
+       LIBS      *= -F$${LIB_PATH}
+       }
+       else {
+
+       unix:lessThan(QT_MAJOR_VERSION, 5) {
+
+            # Many Linux distributions install Qwt in the same directory
+            # as the Qt libs and thus we need to prepend the path for the local build
+            # to avoid conflicting with the installed version.
+            # Qt5 qmake appends ( instead of prepending ) the path to the Qt libs
+            # to LIBS, but for Qt4 we need to use the QMAKE_LIBDIR_FLAGS.
+
+               QMAKE_LIBDIR_FLAGS *= -L$${LIB_PATH}
+       }
+               else {
+                       LIBS *= -L$${LIB_PATH}
+               }
+       }
+
     unset(LINKAGE)

     mac:contains(QWT_CONFIG, QwtFramework) {
@@ -66,6 +88,7 @@
     LIBS += $$LINKAGE
     export(LIBS)
     export(QMAKE_LFLAGS)
+    export(QMAKE_LIBDIR_FLAGS)

     return(true)
 }
Index: designer/designer.pro
===================================================================
--- designer/designer.pro       (revision 2048)
+++ designer/designer.pro       (working copy)
@@ -53,7 +53,6 @@
     contains(QWT_CONFIG, QwtDll) {

         contains(QWT_CONFIG, QwtDesignerSelfContained) {
-
             QWT_CONFIG += include_src
         }

@@ -86,18 +85,8 @@
         # into the plugin. Not supported on Windows !

         QMAKE_RPATHDIR *= $${QWT_INSTALL_LIBS}
+        qwtAddLibrary($${QWT_OUT_ROOT}/lib, qwt)

-        contains(QWT_CONFIG, QwtFramework) {
-
-            LIBS      += -F$${QWT_OUT_ROOT}/lib
-        }
-        else {
-
-            LIBS      += -L$${QWT_OUT_ROOT}/lib
-        }
-
-        qwtAddLibrary(qwt)
-
         contains(QWT_CONFIG, QwtDll) {

             win32 {
Index: qwt.prf
===================================================================
--- qwt.prf     (revision 2048)
+++ qwt.prf     (working copy)
@@ -27,12 +27,11 @@
 contains(QWT_CONFIG, QwtFramework) {

     INCLUDEPATH *= $${QWT_INSTALL_LIBS}/qwt.framework/Headers
-    LIBS        *= -F$${QWT_INSTALL_LIBS}
 }
 else {

     INCLUDEPATH *= $${QWT_INSTALL_HEADERS}
-    LIBS        *= -L$${QWT_INSTALL_LIBS}
 }

-qwtAddLibrary(qwt)
+# QMAKE_RPATHDIR *= $${QWT_INSTALL_LIBS}
+qwtAddLibrary($${QWT_INSTALL_LIBS}, qwt)
Index: examples/examples.pri
===================================================================
--- examples/examples.pri       (revision 2048)
+++ examples/examples.pri       (working copy)
@@ -35,18 +35,8 @@
 }

 QMAKE_RPATHDIR *= $${QWT_OUT_ROOT}/lib
+qwtAddLibrary($${QWT_OUT_ROOT}/lib, qwt)

-contains(QWT_CONFIG, QwtFramework) {
-
-    LIBS      += -F$${QWT_OUT_ROOT}/lib
-}
-else {
-
-    LIBS      += -L$${QWT_OUT_ROOT}/lib
-}
-
-qwtAddLibrary(qwt)
-
 greaterThan(QT_MAJOR_VERSION, 4) {

     QT += printsupport