I took a short look at the code. The declaration for writeError is in
/libraries/SD/utility/SDFat.h
If you want to check, look for this. Line 44 in v0022:
class SdFile : public Print {
public:
/** Create an instance of SdFile. */
SdFile(void) : type_(FAT_FILE_TYPE_CLOSED) {}
/**
* writeError is set to true if an error occurs during a write().
* Set writeError to false before calling print() and/or write() and check
* for true after calls to print() and/or write().
*/
bool writeError;
You might want to look there and see if something has changed.