Define MAMICO_COMMIT_HASH at build time, not at configure time

[rubenhorn]

Avoids mismatch between version info and actual repo state. (Part of #125)

[github-actions]

Sufficient test coverage for changed files.

[Thinkpiet]

Very good idea! 👍

However, this is a lot of code for something very simple. It looks fragile (might not work on system X for surprising reason Y) due to its complexity. Is there really no simpler way?

[rubenhorn]

However, this is a lot of code for something very simple. It looks fragile (might not work on system X for surprising reason Y) due to its complexity. Is there really no simpler way?

This is actually the simplest way to do it.
The whole code generation is written in CMake, so it does not depend on any 3rd party interpreter (Bash, Python, PowerShell).
The logic for generating the version hash has been extracted from the main CMakeLists.txt, which makes this file easier to read in my opinion.
The target mamico just depends on an additional target and include path.

This should really work on any system:

• Cannot execute cmake script? (Impossible, CMake is required.)
• Git is not installed? Skip hash computation and just default to “unknown”.
• Other OS/shell used? Pure CMake commands used. (Delegate responsibility.)

[Thinkpiet]

OK! Please test it on at least 3-4 different machines - if it works then it is approved :-) (For me it works fine)

[rubenhorn]

Tested on:

Device	Architecture	OS	CMake	CXX
My laptop	Intel i7 x86	Ubuntu 24.04.4 LTS	3.28.3	Clang 18.1.8
Minicluster AMD	AMD EPYC x86	Rocky Linux 8.5	3.20.2	GNU 8.5.0
Minicluster ARM	FUJITSU A64FX	Rocky Linux 8.5	3.20.2	GNU 8.5.0
HSUper	Intel Xeon x86	Rocky Linux 8.10	3.27.9	GNU 13.2.0
Google Colab	Intel Xeon x86	Ubuntu 22.04.5 LTS	3.31.10	GNU 11.4.0
My phone1	ARM Cortex aarch64	Android 16	4.2.3	Clang 21.1.8

This should be enough. 😉

Footnotes

1. Using Termux. (Requires -DKokkos_ENABLE_LIBDL=OFF.) ↩