Build script failes on Windows using P4est_jll artifact

[zjwegert]

The build.jl currently fails to find the libp4est library on Windows. This appears to be because P4est_jll creates the .dll files in the artifact directory bin (with a different name from libp4st!) and creates a .dll.a in in lib. The .dll.a files are then not recognised by Libdl.find_library.

A workaround is to modify build.jl as

...
if (cmp(P4EST_LIB,"") == 0)
# Check P4EST_LIB (.../libp4est.so file) exists
    P4EST_LIB = string(Libdl.find_library(P4EST_LIB_NAME,[P4EST_LIB_DIR,P4EST_ROOT_DIR]),".",Libdl.dlext)
    if P4EST_ARTIFACT && (cmp(P4EST_LIB,string(".",Libdl.dlext)) == 0) # Fix for finding dll on Windows
        P4EST_LIB = P4est_jll.get_libp4est_path()
    end
end
...

instead of

...
if (cmp(P4EST_LIB,"") == 0)
# Check P4EST_LIB (.../libp4est.so file) exists
    P4EST_LIB = string(Libdl.find_library(P4EST_LIB_NAME,[P4EST_LIB_DIR,P4EST_ROOT_DIR]),".",Libdl.dlext)
end
...

[JordiManyer]

Hi @zjwegert , thanks for the issue! Unfortunately I do not have access to a windows machine, so you'll have to walk me throught it.

My first impression is that if we are using an artifact, we probably always want to be using the function P4est_jll.get_libp4est_path() to find path. Unfortunately with P4est_jll on linux I cannot seem to have access to that function. Is it something that might be limited to some versions of the artifact?

EDIT: It is showing now, after updating. I can also seem to have access to that function for artifacts on linux for versions 2.2-2.8 (i.e all versions supported). I'm then for using this function whenever we have an artifact.

[JordiManyer]

What do you think @amartinhuertas ?

[JordiManyer]

@zjwegert can you check the PR branch works on windows?

[zjwegert]

@zjwegert can you check the PR branch works on windows?

Done! Works on my machine.