Why `libpng_jll = "<1.6.42"`

[eschnett]

The project dependencies of Gtk4.jl specify libpng_jll = "<1.6.42". Why is this so? Newer versions of libpng_jll exist – was there an incompatibility?

[jwahlstrand]

There's a segfault in CI for windows, i686:

Exception: 
Please submit a bugLrepoN at 0x693f23b6 -- gLrepoNEXCEPTION_ACCESS_VEXCEPTION_ACCESS_VIOLATION at 0x693f23b6 -- png_write_chunk at C:\Users\runneradmin\.julia\artifacts\cf4bb8b591a4b6536f278d82ec951907f6dfef4c\bin\libpng16.dll (unknown line)
in expression starting at D:\a\Gtk4.jl\Gtk4.jl\test\gui\canvas.jl:3
Allocations: 31650869 (Pool: 31649778; Big: 1091); GC: 42
png_read_filter_row_paeth4_sse2 at C:\Users\runneradmin\.julia\artifacts\cf4bb8b591a4b6536f278d82ec951907f6dfef4c\bin\libpng16.dll (unknown line)
in expression starting at D:\a\Gtk4.jl\Gtk4.jl\test\gui\canvas.jl:3
Allocations: 31650869 (Pool: 31649778; Big: 1091); GC: 42
Package Gtk4 errored during testing

CI log with the crash is here: https://github.com/JuliaGtk/Gtk4.jl/actions/runs/14255845427/job/39958274198?pr=92

I don't have a windows 32 bit computer to try to diagnose it, so I just restricted the compat. I was hoping that it would go away as libpng was updated, but perhaps it's time to allow recent versions.

[jwahlstrand]

I removed the restriction for libpng_jll, skipped testing windows 32 bit in CI, and added a note in the README about the crash and how it can be worked around.