371: Compiler Complaint
Title text: Checking whether build environment is sane... build environment is grinning and holding a spatula. Guess not.
A compiler is a program that converts code into machine instructions that a computer can run. A Pointer is a variable within a computer program that is used to reference a memory location. A Segmentation Fault (segfault) is an error that occurs when a program attempts to access an invalid section of memory. Segfaults usually cause a program to crash in an ungraceful fashion and fixing them can be difficult.
In the comic, the computer starts talking to Cueball and compares a segfault with the unpleasant feeling one gets when they experience a hypnic jerk. The computer then tells the programmer to "double-check your damn pointers," as segfaults usually arise from a program attempting to access memory that is referenced by an invalid pointer.
The title-text references GNU-style autoconf configuration scripts. These scripts check certain features of the system they're running on in order to build a program correctly; for example, certain systems expect system calls to occur in a specific way, and the autoconf script will detect this and alter the program to match the expectation. Invariably (and memetically), these scripts include a check to determine "whether the build environment is sane." This actually checks whether a newly created file is older than the script itself, which could indicate a very esoteric filesystem, a corrupted source archive, or just a system clock that's set incorrectly; however, since these file modification dates are an important part of how the autoconf script does its work, it can't go any further in an "insane" environment. In any case, the joke is that an insane build environment is nothing like an insane person, yet Randall is equating the two.
- [Cueball sits at a computer, hand over the keyboard.]
- Computer: Okay, human.
- Cueball: Huh?
- Computer: Before you hit "compile," listen up.
- Computer: You know when you're falling asleep, and you imagine yourself walking or something, and suddenly you misstep, stumble, and jolt awake?
- Cueball: Yeah!
- Computer: Well, that's what a segfault feels like.
- Computer: Double-check your damn pointers, okay?