Gotchas

Modified Time Travel

Be careful with modified time that make relies on. If you hand-modify a target so that it is newer than a prerequisite then make will not use its recipe to build the target. This is easy to do inadvertently with a git GUI tool when discarding changes or by doing a git restore <project-name>. As git advances the modified time, this is effectively the same as touch <project-name>. To recover from this situation, either;

• Remove the target with rm <project-name>.
• Run make with its --always-make flag but be careful with this if bootstrapping updo itself within the makefile.