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Save-only error on newly registered file type with custom package #440
Description
@maucejo 's https://github.com/maucejo/UFFFiles.jl was recently merged into the FileIO registry.
For my work, I have a custom package that handles similar files.
To handle the load / save logic, so far, I used the following in my package.
function load(f::File{format"UNV"})
...
end
function save(f::File{format"UNV"}, data)
...
end
detect_unv(io) = endswith(io.name, ".unv>") || endswith(io.name, ".uff>")
function __init__()
add_format(format"UNV", detect_unv, [".unv", ".uff"], [MyPackage])
endSince 1.18, which is the introduction of UFFFiles in the registry, my tests fail for save, but load works fine.
ERROR: ArgumentError: Package UFFFiles [20c5726e-8372-4c34-be2c-190a5a70d483] is required but does not seem to be installed
I could have expected that both success (as in previous FileIO versions) or fail, but I don't understand a partial fail.
Any ideas what could be the reason ?
I've attempted to make a MWE, but in a module, not totally a package, so the init-equivalent step may not be relevant as such.
using Pkg
Pkg.activate("TestFileIO")
Pkg.add(name="FileIO", version="1.17")
unvname = joinpath(tempdir(), "test.unv")
write(unvname, "test")
module TempFileIO
using FileIO
function load(f::File{FileIO.format"UNV"})
open(f, "r") do s
String(take!(s.io))
end
end
function save(f::File{FileIO.format"UNV"}, data)
open(f, "w") do s
write(s.io, data)
end
end
detect_unv(io) = endswith(io.name, ".unv>") || endswith(io.name, ".uff>")
add_loader(format"UNV", detect_unv, [".unv", ".uff"], [TempFileIO])
end
using .TempFileIO
using FileIO
load(unvname) # Works regardless of version
save(unvname, "test") # Fails in 1.18+ since UFF is registered
Activity
maucejo commentedon Jun 3, 2026
Hi @BambOoxX. I am usure about the roots of this partial fail. What I can tellement you is that the changes I made to FileIO are minor and follow the guidelines. From the UFFFiles side, I have implemented the save\load logic using these lines:
I observe that in the save function I have
format"UFF"instead ofFileIO.format"UFF". I think that it is the root of your problem.I will fix that on Friday.
Could you tell me if this change fix your issue?