I read about it as a boy in a Tom Clancy novel:
KGB knocks on the door of Eagle Dynamics. Yoyo, sporting a pony tail and Birkenstocks, calls out in a whisper to his colleagues: "We've got company."
Yoyo opens the door and snow flakes flurry inside. The unnamed KGB officer takes two steps into the room and stops. With hands hidden in his trench coat, he surveys the room for a brief moment, and smirks. He says only one name: "Blackshark."
"B-b-but the Flanker, we were promised!" stammers Chizh.
"Black-Shark!" repeats the KGB officer. He narrows his eyes, stares down Chizh, turns and leaves as abruptly as he arrived.
...later on in the story, Jack Ryan makes contact with an ED team member in Switzerland and he learns of the original plans for a full-switch Su-27 with R-77s. The code was only "2 weeks" away from being finished, but the only physical copy resides on 3.5" floppy disks in a Moscow vault.
To be continued...