Looks like you might need to update the preferred_gcc_version?

Hmm since this changes the DLL name from libproj_9_3.dll to libproj_9_4.dll it is breaking on Windows. It needed the version_offset major version to be bumped like in #7366. We should probably write this in a comment next to the version numbers.

Now that it is out, I guess General needs to be updated to block PROJ_jll 901.400? Or better to just yank it?

Is it actually incompatible? Would changing the library name on Windows to libproj_9_3.dll be another option?

I think it is only the library name on Windows that is the issue I think. The PROJ_SOVERSION is the same so the ABI should otherwise be the same.

That's also how the release notes read. Should we then rename the Windows libraries (and add respective comments) instead of blocking or yanking the package?

I'd be fine with that if others agree. It seems like the smoothest upgrade path. I tried locally renaming the DLL in the artifact, and dev PROJ_jll with the same renames. That didn't work yet however, it is not clear why:

julia> using GDAL_jll
ERROR: InitError: could not load library "C:\Users\visser_mn\.julia\artifacts\415bbbe8ca2ee27f90b17984069673e280f25d0d\bin\libgdal-35.dll"
The specified module could not be found.

Note that GDAL_jll has a PROJ_jll dependency, but also via libgeotiff_jll. It is libgeotiff_jll that gives the errors: yeesian/ArchGDAL.jl#427

Of course it could be confusing that PROJ 9.4 has a libproj_9_3.dll. Going forward I'd rather not have the minor version in the name. As far as I can see this is not configurable, but we could ask upstream or patch ourselves:

https://github.com/OSGeo/PROJ/blob/9.4.0/cmake/ProjVersion.cmake#L40-L46
https://github.com/OSGeo/PROJ/blob/9.4.0/cmake/ProjUtilities.cmake#L37-L63
OSGeo/PROJ#3066

Actually the libgdal-35.dll seems to be a separate issue affecting the new GDAL_jll versions, because forcing [email protected] does not resolve that. Users need to downgrade both; add [email protected] [email protected].

I propose we yank these two broken/breaking releases; JuliaRegistries/General#107721

Regarding the libproj DLL name, I also created an upstream issue: OSGeo/PROJ#4151

Is it actually incompatible? Would changing the library name on Windows to libproj_9_3.dll be another option?

Unfortunately that does not work on Windows because the dll name in embedded in the dll itself.

Thanks @joa-quim. Let's move discussion to #8780.