Changing link entry doesn't trigger relinking targets

Consider this section in fpm.toml

[build]
link = ["lapack", "blas"]

I can run fpm build, etc. When I change the section to

[build]
link = ["lapack", "openblas"]

then fpm build doesn't link the project using the new settings (nothing happens).

[LKedward]

Hi @brocolis, can you try without lapack, just openblas on its own? I don't think you need both lapack and openblas together.

Hi @LKedward, it doesn't work either. I also tried link = ["nonexistent", "nonono"] , nothing happens.

It looks like I have to delete the build subdirectory and build everything from the start.

[awvwgk]

I think the issue is that the manifest is currently not hashed, but probably should be. We could either hash the complete the fpm.toml and always rebuild on any change (lot's of unnecessary rebuiilds) or hash relevant sections like build.link or the link entry in the targets and have the link step depend on this change.

[LKedward]

Ah yes of course. Agreed, we should hash the relevant sections of the manifest.

[awvwgk]

A good mechanism for this would be to use a different output directory for the executables which additionally depends on the link arguments and not only on the compile arguments.

I talked with Jakub @kubajj about this in the context of the compiler profiles, the different build directories implemented there would provide the required mechanism to resolve this and would also provide a way to get the first part of the compiler profiles into fpm.

[kubajj]

So if I understood correctly, do we need to add the hash of build.link into the build name directory of the executable that depends on the link target?