Sometimes you write:

/* XXX temporary hack, fix later */

Then you come back in a few days and fix or refactor that part.

Or you don’t. I’ve grepped the Linux kernel source code and found the oldest temporary hack still lurking there to be 20 years old.

Yup, 20 years. A temporary fix for an Atari graphic card in arch/m68k/atari/config.c:

/* This is a temporary hack: If there is Falcon video
 * hardware, we assume that the ST-DMA serves SCSI instead of
 * ACSI. In the future, there should be a better method for
 * this...
 */
ATARIHW_SET(ST_SCSI);
printk("STDMA-SCSI ");

It appeared first in the 1.3.94 kernel version, released on April 22, 1996 (download).

So, how temporary are the temporary kludges in YOUR code?