On the other hand, you could consider it a cautionary tale about not reinventing wheels, because a problem that may seem trivial at first often turns out to be far more complex than expected.
This is why you try to re-use work when possible, rather than endlessly reinventing things, because while sure, adding a comma to the printf string is easy enough, your assumptions (English locale, compiler not trying to be clever) are going to quickly become visible as things fall apart because your assumptions aren't in line with the system's assumptions.
What this story really demonstrates is that without a clear understanding of how a system is designed and the basic assumptions it makes, just "hacking on the code" is just as likely to break things as it is to fix them.
You assume that systems tend to be well-designed and the basic assumptions it makes are justifiable, and that the systems faithfully implement that design and those assumptions.
It sounds like the author found a bunch of bugs in the process of making a simple code change. That happens pretty frequently, and doesn't mean that the author should let the priests of the cathedral deal with this UNIX thing that is too complicated for the laity to hack on. It just means there is no priesthood.
This is why you try to re-use work when possible, rather than endlessly reinventing things, because while sure, adding a comma to the printf string is easy enough, your assumptions (English locale, compiler not trying to be clever) are going to quickly become visible as things fall apart because your assumptions aren't in line with the system's assumptions.
What this story really demonstrates is that without a clear understanding of how a system is designed and the basic assumptions it makes, just "hacking on the code" is just as likely to break things as it is to fix them.