The questions states the problem. I have managed to make legacy versions of gmmlib and igc in the repo for fedora 42 and rawhide. But when I try to build compute-runtime, it throws errors and fails. I somebody can help me. Please do so. I will provide the logs and my GitHub repository if asked.
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You should just do that now, the more information you provide, the easier it is for someone to help.
Wait. Lemme turn my laptop on.
I found a mistake in the spec file. I accidently misspelled a dependency.
I’d like to applause to your packaging of -legacy packages into the copr. If I may have a few tips:
If you wanted to go that route, you could progress with submitting it into Fedora repositories proper. For that case, you’d have to add conflicts with the non-legacy packages to both igc, and compute-runtime. And, at some point in the future, legacy packages would also need:
But, these two points shouldn’t be necessary now.
Wow. Aren’t you the maintainer of the official package (intel-compute-runtime).Nice to meet you, Sir. I did have this idea of building the intel-igc-legacy. I have a package for it. But it somehow builds with the latest IGC. I read a lot of docs (more like I asked ai to shorten them for me as I was short on time.) to build this. I know that I should not fiddle with the intel-gmmlib-legacy. It will break the support for the intel-media-driver and some other stuff. I kept it just in case. I managed to patch the compute-runtime to support gcc 15. ( I took those patches from the aur because it would take me a lot of time to read logs for hours and find these issues, fix and diff and then patch. I just did the fastest and easiest thing. I was doing exactly that and I just reminded me that the patches were available in the aur. I downloaded them and voila, it worked perfectly and fixed all issues that I would have had to fix manually. ) Finally, after fiddling for 2 more days, I did see that I could build with newer gmmlib. After fiddling for 1 more day, I realized, I could just patch the errors and use newer igc to build.
I am thinking about submitting it to real fedora repos AND ADD CONFLICTS as I installed both latest and legacy on my system by accident and it wreaked my system and forced me to reinstall.
I am kind of scared of maintaining a package that many people could rely on. If I mess up, I could potentially break someone’s OS. Again, I am not a developer. I am just a high school student. I just learned that you could fix issues by reading logs and docs. And going through the tedious process of patching and fixing. I am thinking about building with the igc legacy. But it will install the old opencl version.
Finally, what kinds of issues would I have to deal with to build with the latest IGC?
I will start reading docs for the spirv llvm and the opencl clang.
Nice to meet you too! 
So, I’ve sent a PR: Assorted fixes by frantisekz · Pull Request #1 · SmARtuser69/intel-opencl-legacy-fedora · GitHub
If you build intel-igc-legacy first in your copr repo, then build the compute-runtime with changes from the linked PR, it should work and correctly pull/depend on igc-legacy package.
There is no need to worry about packaging, if you won’t be actively trying, you shouldn’t break anybody’s OS too hard 
But starting with copr is just fine also, I see quite a few already downloaded/are using your copr repo, so that’s great!
I merged it. I will maintain it only in the copr repo for now.