libxml2: Work around lxml API misuse

[jtojnar]

Motivation for this change

https://gitlab.gnome.org/GNOME/libxml2/issues/255
cc @jonringer @vcunat

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Added a release notes entry if the change is major or breaking
• Fits CONTRIBUTING.md.

[vcunat]

x86_64-darwin rebuild? I suppose that would mean we can't get this to nixpkgs master within the next several days.

[r-rmcgibbo]

Result of nixpkgs-review pr 123890 at 60ef58e run on x86_64-linux 1

1466 packages marked as broken and skipped:

• adobe-reader
• adoptopenjdk-hotspot-bin-13
• adoptopenjdk-hotspot-bin-14
• adoptopenjdk-jre-hotspot-bin-13
• adoptopenjdk-jre-hotspot-bin-14
• adoptopenjdk-jre-openj9-bin-13
• adoptopenjdk-jre-openj9-bin-14
• adoptopenjdk-openj9-bin-13
• adoptopenjdk-openj9-bin-14
• agdaPackages.iowa-stdlib
• ...

22788 packages skipped due to time constraints:

• AusweisApp2
• CHOWTapeModel
• DisnixWebService
• EBTKS
• EmptyEpsilon
• Fabric (python38Packages.Fabric)
• LAStools
• LASzip
• LASzip2
• Literate
• ...

82 packages built successfully:

• asciidoc
• brotli
• cmake
• curl
• dav1d
• docbook2x
• e2fsprogs
• eigen
• epoxy
• fribidi
• giflib
• gnu-efi
• graphite2
• ilmbase
• itstool
• json_c
• kmod
• lcms2
• libGL
• libarchive
• libcbor
• libdevil-nox
• libglvnd
• libipt
• libjpeg (libjpeg_turbo)
• libmicrodns
• libmng
• libstemmer
• libsysprof-capture
• libtiff
• libuuid (util-linuxMinimal)
• libvdpau
• libwebp
• llvmPackages_11.libcxx (llvmPackages_latest.libcxx)
• llvmPackages_11.libcxxabi (llvmPackages_latest.libcxxabi)
• llvmPackages_11.libunwind (llvmPackages_latest.libunwind)
• llvmPackages_12.libcxx
• llvmPackages_12.libcxxabi
• llvmPackages_12.libunwind
• mobile-broadband-provider-info
• ninja
• openexr
• opensp
• pciutils
• poppler_data
• python38Packages.libxml2
• python38Packages.libxslt
• soxr
• su
• volk
• vulkan-headers
• woff2
• xhtml1
• xkeyboard_config (xorg.xkeyboardconfig)
• xmlto
• xorg.libICE
• xorg.libSM
• xorg.libX11
• xorg.libXScrnSaver
• xorg.libXau
• xorg.libXcomposite
• xorg.libXcursor
• xorg.libXdamage
• xorg.libXdmcp
• xorg.libXext
• xorg.libXfixes
• xorg.libXi
• xorg.libXinerama
• xorg.libXrandr
• xorg.libXrender
• xorg.libXt
• xorg.libXtst
• xorg.libXv
• xorg.libXxf86vm
• xorg.libxcb
• xorg.xcbutil
• xorg.xcbutilimage
• xorg.xcbutilkeysyms
• xorg.xcbutilrenderutil
• xorg.xcbutilwm
• xorg.xorgproto
• zeromq (zeromq4)

[jonringer]

x86_64-darwin rebuild? I suppose that would mean we can't get this to nixpkgs master within the next several days.

branch off should be done in the next 24 hours, see https://discourse.nixos.org/t/21-05-release-schedule/12528/3.

Next staging cycle will occur soon after.

[jonringer]

https://github.com/NixOS/nixpkgs/pull/123890

1 package built:
python3Packages.lxml

[erictapen]

Was backported to staging-21.05 in 1b1608a.

[vojta001]

Hello, can we please cherry-pick it to master or somehow make it available in nixos-unstable? It's been in staging for ages and build failures prevent me from updating

[jtojnar]

That is not possible without triggering a massive rebuilds for everyone.

[vojta001]

Oh, I understand now. That's a bit unfortunate though

[vcunat]

I'd expect that it gets there this week. (inside PR #124095)