Fix compiler warnings in exception messages
Fix compiler warnings in exception messages

Futrell/pyrsistent,jkbjh/pyrsistent,jml/pyrsistent,tobgu/pyrsistent,tobgu/pyrsistent,jkbjh/pyrsistent,jml/pyrsistent,tobgu/pyrsistent,jkbjh/pyrsistent,Futrell/pyrsistent,jml/pyrsistent,Futrell/pyrsistent