> In the beginning of Unix, m4 was created. This has made many people very angry and has been widely regarded as a bad move.

autoconf creates a shell script by preprocessing with m4. So you need to know not just the intricacies of shell scripting, but also of m4, with its arcane rules for escaping: https://mbreen.com/m4.html#quotes

If autoconf used m4 to generate python scripts, they would also look like https://pyobfusc.com/#winners