Ensure that correct python version is used for build

PYTHON_DESIRED can be either "2", "3" or a path to interpreter

CMakeLists.txt

@@ -1,20 +1,20 @@
 PROJECT (dnf-plugins-extras NONE)
 CMAKE_MINIMUM_REQUIRED (VERSION 2.4)
 
-if (NOT PYTHON_DESIRED)
-    set (PYTHON_DESIRED "2")
-endif()
-
-if (${PYTHON_DESIRED} STREQUAL "2")
-	FIND_PACKAGE (PythonInterp REQUIRED)
-else()
-	SET(Python_ADDITIONAL_VERSIONS 3.3)
-	FIND_PACKAGE(PythonLibs 3.0)
-	FIND_PACKAGE(PythonInterp 3.0 REQUIRED)
-endif()
+IF (NOT PYTHON_DESIRED)
+    FIND_PACKAGE (PythonInterp REQUIRED)
+ELSEIF (${PYTHON_DESIRED} STREQUAL "2")
+    FIND_PACKAGE (PythonInterp 2 EXACT REQUIRED)
+ELSEIF (${PYTHON_DESIRED} STREQUAL "3")
+    FIND_PACKAGE (PythonInterp 3 EXACT REQUIRED)
+ELSEIF (EXISTS ${PYTHON_DESIRED})
+    SET (PYTHON_EXECUTABLE ${PYTHON_DESIRED})
+    FIND_PACKAGE (PythonInterp REQUIRED)
+ELSE ()
+    MESSAGE (FATAL_ERROR "Invalid PYTHON_DESIRED value: " ${PYTHON_DESIRED})
+ENDIF()
 
 EXECUTE_PROCESS(COMMAND ${PYTHON_EXECUTABLE} -c "from sys import stdout; from distutils import sysconfig; stdout.write(sysconfig.get_python_lib())" OUTPUT_VARIABLE PYTHON_INSTALL_DIR)
-EXECUTE_PROCESS(COMMAND ${PYTHON_EXECUTABLE} -c "import sys; sys.stdout.write('%s.%s' % (sys.version_info.major, sys.version_info.minor))" OUTPUT_VARIABLE PYTHON_MAJOR_DOT_MINOR_VERSION)
 MESSAGE(STATUS "Python install dir is ${PYTHON_INSTALL_DIR}")
 
 SET (SYSCONFDIR /etc)

dnf-plugins-extras.spec

@@ -276,13 +276,13 @@ mkdir python3
 
 %build
 pushd python2
-  %cmake ..
+  %cmake .. -DPYTHON_DESIRED:FILEPATH=%{__python2}
   %make_build
   make doc-man
 popd
 %if %{with python3}
 pushd python3
-  %cmake -DPYTHON_DESIRED:str=3 ..
+  %cmake .. -DPYTHON_DESIRED:FILEPATH=%{__python3}
   %make_build
   make doc-man
 popd

doc/CMakeLists.txt

@@ -16,8 +16,8 @@ INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/dnf.plugin.kickstart.8
     ${CMAKE_CURRENT_BINARY_DIR}/dnf.plugin.system-upgrade.8
     ${CMAKE_CURRENT_BINARY_DIR}/dnf.plugin.tracer.8
 	DESTINATION share/man/man8)
-if (${PYTHON_DESIRED} STREQUAL "3")
-INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/dnf.plugin.rpmconf.8
-    ${CMAKE_CURRENT_BINARY_DIR}/dnf.plugin.torproxy.8
-	DESTINATION share/man/man8)
+if (${PYTHON_VERSION_MAJOR} STREQUAL "3")
+    INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/dnf.plugin.rpmconf.8
+        ${CMAKE_CURRENT_BINARY_DIR}/dnf.plugin.torproxy.8
+        DESTINATION share/man/man8)
 endif()

etc/dnf/plugins/CMakeLists.txt

@@ -1,4 +1,4 @@
-if (${PYTHON_DESIRED} STREQUAL "3")
+if (${PYTHON_VERSION_MAJOR} STREQUAL "3")
 INSTALL (FILES torproxy.conf DESTINATION ${SYSCONFDIR}/dnf/plugins)
 INSTALL (FILES rpmconf.conf DESTINATION ${SYSCONFDIR}/dnf/plugins)
 endif()

plugins/CMakeLists.txt

@@ -1,4 +1,4 @@
-if (${PYTHON_DESIRED} STREQUAL "3")
+if (${PYTHON_VERSION_MAJOR} STREQUAL "3")
 INSTALL (FILES rpm_conf.py DESTINATION ${PYTHON_INSTALL_DIR}/dnf-plugins)
 INSTALL (FILES torproxy.py DESTINATION ${PYTHON_INSTALL_DIR}/dnf-plugins)
 endif()