As described in https://discourse.julialang.org/t/ann-plans-for-removing-packages-that-do-not-yet-support-1-0-from-the-general-registry/ we are planning on removing packages that do not support 1.0 from the General registry. This package has been detected to not support 1.0 and is thus slated to be removed. The removal of packages from the registry will happen approximately a month after this issue is open.

To transition to the new Pkg system using Project.toml, see https://github.com/JuliaRegistries/Registrator.jl#transitioning-from-require-to-projecttoml.
To then tag a new version of the package, see https://github.com/JuliaRegistries/Registrator.jl#via-the-github-app.

If you believe this package has erroneously been detected as not supporting 1.0 or have any other questions, don't hesitate to discuss it here or in the thread linked at the top of this post.

While the package works, the tests fail right now because DiffEqDevTools no longer requires FiniteElementDiffEq, but needs to create sub-meshes for convergence (if you add using FiniteElementDiffEq to DiffEqDevTools, tests will pass). The best way to go about this is to have some kind of FEMMeshes package which has all of the meshing tools, and then have this be a separate package just for solving problems on the meshes. This would reduce the mixup here because half of the functionality is solving PDEs, while the other half is just making meshes, and this should really just be solving.