py3: use sysstr() to convert ProgrammingError bytes with no unicode error risk
msg.decode('utf8') may fail if msg isn't an ASCII string, and that's possible
as we sometimes embed a filename in the error message for example.
fixbundle() {
grep -v 'saving bundle' | grep -v 'saved backup' | \
grep -v added | grep -v adding | \
grep -v "unable to find 'e' for patching" | \
grep -v "e: No such file or directory" | \
cat
}