ccflags seems not ok

[guilvge]

hi: when I use pygccxml, I used the code may cause some warning but error, and I know use which flag to fixed it. for example: the code will show me [-Wnull-conversion], I can use flag " -Wno-null-conversion" to revert it, so I pass it in ccflags=-Wno-null-conversion, but it is not ok, the last cmd will like: "/usr/bin/castxml" -I"." -c -x c++ --castxml-cc-gnu "(" /usr/bin/clang++ -Wno-null-conversion ")" --castxml-gccxml -o /tmp/tmpxpsi9e2o.xml xxx, but it should be: ""/usr/bin/castxml" -I"." -c -x c++ -Wno-null-conversion --castxml-cc-gnu "(" /usr/bin/clang++ ")" --castxml-gccxml -o /tmp/tmpxpsi9e2o.xml xxx", the warning log will disapper by using this command. so I'm confused why the property "ccflags" not work.