Hello,
I have wrote the attached patch for following FIXME in file src/cp.c -
/* FIXME: consider not calling getenv for SIMPLE_BACKUP_SUFFIX unless
we'll actually use backup_suffix_string. */
backup_suffix_string = getenv ("SIMPLE_BACKUP_SUFFIX");
Since we use backup_suffix_string to duplicate it into simple_backup_suffix, I brought the getenv() call there, that too, only if required (as simple_backup_suffix already stores tilde already).
I did 'diff -ur' directly against original cp.c (named cp-original.c, then) to create the patch. I tested patch using -b, --backup and --suffix option of c. Version I have used is latest one on
savannah.gnu.org - coreuitls-8.25.
There was cppi (didn't know what it does) at the bottom of coreutil's download page. After reading it's README, I concluded that it is not to be considered while debugging/fixing coreutils. Hopefully, I was correct in doing so.
If incorrect, please do correct me in any case. :)