Be Aware of the Makefile Effect

Make and Makefiles are incredibly simple when they are not autogenerated by autoconf. If they are generated by autoconf, don’t modify them, they are a build artifact. But also, ditch autoconf if you can.

In the broader sense: yes this effect is very real. You can fall to it or you can exploit it. How I exploit it: write a bit of code (or copy/paste it from somewhere). Use it in a project. Refine as needed. When starting the next project, copy that bit of code in. Modify for the second project. See if changes can be backported to the original project. Once both are running and are in sync, extract the bit of code and make it into a library. Sometimes this takes more projects to distill the thing into what a library should be. In the best case, open source the library so others can use it.

They are also extremely limited. Timestamp-based freshness is often broken by modern VCSes. Git doesn’t record timestamps internally, so files can (and often do) have their mtime updated even when their contents are the same, causing unnecessary rebuilds.

They also are utterly unable to handle many modern tools whose inputs and/or outputs are entire directories or whose output names are not knowable in advance of running the tool.

I love make. I have put it to good use in spite of its shortcomings and know all the workarounds for them, and the workarounds for the workarounds, and the workarounds for those workarounds. Making a correct Makefile when you end up with tools that don’t perfectly fit into its expectations escalates rapidly in difficulty and complexity.