Debugging Configure

An anonymous reader writes "All too often, checking the README of a package yields only the none-too-specific "Build Instructions: Run configure, then run make." But what about when that doesn't work? In this article, the author discusses what to do when an automatic configuration script doesn't work -- and what you can do as a developer to keep failures to a minimum. After all, if your build process doesn't work, users are just as badly off as if your program doesn't work once it's built."

Comments

The webpage missed a major resource

[devphil]

The GNU Autotools have their own published book, the electronic edition of which is online. This doesn't seem to be listed in the resources at the end of the article.

Backwards

[devphil]

Rather than attempting to include support for every architecture via autoconf,
[...]
Rather than doing a poor job of supporting every platform, it makes much more sense to support one platform directly,

That's exactly how autoconf doesn't work. "Including support for every architecture" is how previous build systems worked, like xmake. Those were an unmitigated disaster.

Automake's goal is to allow the build system to adapt itself to whatever system happens to be available. It does not look at the OS and say, hey, I'm on Solaris, bring out these hardcoded settings. Instead it performs tests for each feature of interest -- where is the compiler? where are the SSL libraries? what's the exact function signature for this not-quite-standard-C subroutine? If your system has been customized from the factory default, so to speak, then hardcoded answers will be wrong, no matter how dilligently those porting people were in originally deriving them.

The idea is to have configure discover whatever the correct answers are, and set variables appropriately so that you don't have to care about the differences -- you can write the code once, as you say, and let the automatics do the necessary adjustments, rather than other people. Assume you're running on a POSIX system, for example, and let configure #define things as necessary to make up for the non-POSIX systems.