Possible Inkscape + [email protected] Bug?

[Xaldew]

Output of brew config

% brew config
HOMEBREW_VERSION: 4.3.24-11-gb678320
ORIGIN: https://github.com/Homebrew/brew
HEAD: b6783204e874ee7c79335bd04d0e1c4eb96f62ab
Last commit: 21 hours ago
Core tap HEAD: d48b7d1f65184b172e2e8f91b92f19d79a21e27a
Core tap last commit: 22 hours ago
Core tap JSON: 24 Sep 12:00 UTC
Core cask tap HEAD: 0a3b4528788b7db4f4799ce9f02a374b47e96803
Core cask tap last commit: 22 hours ago
Core cask tap JSON: 24 Sep 12:00 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_DISPLAY: /private/tmp/com.apple.launchd.H4lmfli3Bd/org.xquartz:0
HOMEBREW_EDITOR: emacsclient --tty --alternate-editor=""
HOMEBREW_MAKE_JOBS: 8
HOMEBREW_SORBET_RUNTIME: set
Homebrew Ruby: 3.3.4 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/3.3.4_1/bin/ruby
CPU: octa-core 64-bit arm_firestorm_icestorm
Clang: 15.0.0 build 1500
Git: 2.46.1 => /opt/homebrew/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 14.6.1-arm64
CLT: 15.3.0.0.1.1708646388
Xcode: N/A
Rosetta 2: false

Output of brew doctor

% brew doctor
Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry or file an issue; just ignore this. Thanks!

Warning: Some installed formulae are deprecated or disabled.
You should find replacements for the following formulae:
  [email protected]
  python-lxml

Warning: Unbrewed dylibs were found in /usr/local/lib.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae and may need to be deleted.

Unexpected dylibs:
  /usr/local/lib/libMoltenVK.dylib
  /usr/local/lib/libSPIRV-Tools-shared.dylib
  /usr/local/lib/libVkLayer_api_dump.dylib
  /usr/local/lib/libVkLayer_device_simulation.dylib
  /usr/local/lib/libVkLayer_khronos_synchronization2.dylib
  /usr/local/lib/libVkLayer_khronos_validation.dylib
  /usr/local/lib/libdxcompiler.3.7.dylib
  /usr/local/lib/libshaderc_shared.1.dylib
  /usr/local/lib/libspirv-cross-c-shared.0.48.0.dylib
  /usr/local/lib/libvulkan.1.2.198.dylib

Warning: Unbrewed header files were found in /usr/local/include.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae and may need to be deleted.

Unexpected header files:
  /usr/local/include/dxc/Support/WinAdapter.h
  /usr/local/include/dxc/dxcapi.h
  /usr/local/include/glslang/HLSL/hlslAttributes.h
  /usr/local/include/glslang/HLSL/hlslGrammar.h
  /usr/local/include/glslang/HLSL/hlslOpMap.h
  /usr/local/include/glslang/HLSL/hlslParseHelper.h
  /usr/local/include/glslang/HLSL/hlslParseables.h
  /usr/local/include/glslang/HLSL/hlslScanContext.h
  /usr/local/include/glslang/HLSL/hlslTokenStream.h
  /usr/local/include/glslang/HLSL/hlslTokens.h
  /usr/local/include/glslang/Include/BaseTypes.h
  /usr/local/include/glslang/Include/Common.h
  /usr/local/include/glslang/Include/ConstantUnion.h
  /usr/local/include/glslang/Include/InfoSink.h
  /usr/local/include/glslang/Include/InitializeGlobals.h
  /usr/local/include/glslang/Include/PoolAlloc.h
  /usr/local/include/glslang/Include/ResourceLimits.h
  /usr/local/include/glslang/Include/ShHandle.h
  /usr/local/include/glslang/Include/SpirvIntrinsics.h
  /usr/local/include/glslang/Include/Types.h
  /usr/local/include/glslang/Include/arrays.h
  /usr/local/include/glslang/Include/glslang_c_interface.h
  /usr/local/include/glslang/Include/glslang_c_shader_types.h
  /usr/local/include/glslang/Include/intermediate.h
  /usr/local/include/glslang/MachineIndependent/Initialize.h
  /usr/local/include/glslang/MachineIndependent/LiveTraverser.h
  /usr/local/include/glslang/MachineIndependent/ParseHelper.h
  /usr/local/include/glslang/MachineIndependent/RemoveTree.h
  /usr/local/include/glslang/MachineIndependent/Scan.h
  /usr/local/include/glslang/MachineIndependent/ScanContext.h
  /usr/local/include/glslang/MachineIndependent/SymbolTable.h
  /usr/local/include/glslang/MachineIndependent/Versions.h
  /usr/local/include/glslang/MachineIndependent/attribute.h
  /usr/local/include/glslang/MachineIndependent/gl_types.h
  /usr/local/include/glslang/MachineIndependent/glslang_tab.cpp.h
  /usr/local/include/glslang/MachineIndependent/iomapper.h
  /usr/local/include/glslang/MachineIndependent/localintermediate.h
  /usr/local/include/glslang/MachineIndependent/parseVersions.h
  /usr/local/include/glslang/MachineIndependent/preprocessor/PpContext.h
  /usr/local/include/glslang/MachineIndependent/preprocessor/PpTokens.h
  /usr/local/include/glslang/MachineIndependent/propagateNoContraction.h
  /usr/local/include/glslang/MachineIndependent/reflection.h
  /usr/local/include/glslang/Public/ShaderLang.h
  /usr/local/include/glslang/SPIRV/GLSL.ext.AMD.h
  /usr/local/include/glslang/SPIRV/GLSL.ext.EXT.h
  /usr/local/include/glslang/SPIRV/GLSL.ext.KHR.h
  /usr/local/include/glslang/SPIRV/GLSL.ext.NV.h
  /usr/local/include/glslang/SPIRV/GLSL.std.450.h
  /usr/local/include/glslang/SPIRV/GlslangToSpv.h
  /usr/local/include/glslang/SPIRV/Logger.h
  /usr/local/include/glslang/SPIRV/NonSemanticDebugPrintf.h
  /usr/local/include/glslang/SPIRV/SPVRemapper.h
  /usr/local/include/glslang/SPIRV/SpvBuilder.h
  /usr/local/include/glslang/SPIRV/SpvTools.h
  /usr/local/include/glslang/SPIRV/bitutils.h
  /usr/local/include/glslang/SPIRV/disassemble.h
  /usr/local/include/glslang/SPIRV/doc.h
  /usr/local/include/glslang/SPIRV/hex_float.h
  /usr/local/include/glslang/SPIRV/spvIR.h
  /usr/local/include/glslang/build_info.h
  /usr/local/include/shaderc/env.h
  /usr/local/include/shaderc/shaderc.h
  /usr/local/include/shaderc/status.h
  /usr/local/include/shaderc/visibility.h
  /usr/local/include/spirv-tools/libspirv.h
  /usr/local/include/spirv_cross/GLSL.std.450.h
  /usr/local/include/spirv_cross/spirv.h
  /usr/local/include/spirv_cross/spirv_cross_c.h
  /usr/local/include/vk_video/vulkan_video_codec_h264std.h
  /usr/local/include/vk_video/vulkan_video_codec_h264std_decode.h
  /usr/local/include/vk_video/vulkan_video_codec_h264std_encode.h
  /usr/local/include/vk_video/vulkan_video_codec_h265std.h
  /usr/local/include/vk_video/vulkan_video_codec_h265std_decode.h
  /usr/local/include/vk_video/vulkan_video_codec_h265std_encode.h
  /usr/local/include/vk_video/vulkan_video_codecs_common.h
  /usr/local/include/vulkan/vk_enum_string_helper.h
  /usr/local/include/vulkan/vk_icd.h
  /usr/local/include/vulkan/vk_layer.h
  /usr/local/include/vulkan/vk_platform.h
  /usr/local/include/vulkan/vk_sdk_platform.h
  /usr/local/include/vulkan/vulkan.h
  /usr/local/include/vulkan/vulkan_android.h
  /usr/local/include/vulkan/vulkan_beta.h
  /usr/local/include/vulkan/vulkan_core.h
  /usr/local/include/vulkan/vulkan_directfb.h
  /usr/local/include/vulkan/vulkan_fuchsia.h
  /usr/local/include/vulkan/vulkan_ggp.h
  /usr/local/include/vulkan/vulkan_ios.h
  /usr/local/include/vulkan/vulkan_macos.h
  /usr/local/include/vulkan/vulkan_metal.h
  /usr/local/include/vulkan/vulkan_screen.h
  /usr/local/include/vulkan/vulkan_vi.h
  /usr/local/include/vulkan/vulkan_wayland.h
  /usr/local/include/vulkan/vulkan_win32.h
  /usr/local/include/vulkan/vulkan_xcb.h
  /usr/local/include/vulkan/vulkan_xlib.h
  /usr/local/include/vulkan/vulkan_xlib_xrandr.h

Warning: Unbrewed static libraries were found in /usr/local/lib.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae and may need to be deleted.

Unexpected static libraries:
  /usr/local/lib/libGenericCodeGen.a
  /usr/local/lib/libHLSL.a
  /usr/local/lib/libMachineIndependent.a
  /usr/local/lib/libOGLCompiler.a
  /usr/local/lib/libOSDependent.a
  /usr/local/lib/libSPIRV-Tools-link.a
  /usr/local/lib/libSPIRV-Tools-lint.a
  /usr/local/lib/libSPIRV-Tools-opt.a
  /usr/local/lib/libSPIRV-Tools-reduce.a
  /usr/local/lib/libSPIRV-Tools.a
  /usr/local/lib/libSPIRV.a
  /usr/local/lib/libSPVRemapper.a
  /usr/local/lib/libglslang-default-resource-limits.a
  /usr/local/lib/libglslang.a
  /usr/local/lib/libshaderc.a
  /usr/local/lib/libshaderc_combined.a
  /usr/local/lib/libshaderc_util.a
  /usr/local/lib/libspirv-cross-c.a
  /usr/local/lib/libspirv-cross-core.a
  /usr/local/lib/libspirv-cross-cpp.a
  /usr/local/lib/libspirv-cross-glsl.a
  /usr/local/lib/libspirv-cross-hlsl.a
  /usr/local/lib/libspirv-cross-msl.a
  /usr/local/lib/libspirv-cross-reflect.a
  /usr/local/lib/libspirv-cross-util.a

Warning: You have unlinked kegs in your Cellar.
Leaving kegs unlinked can lead to build-trouble and cause formulae that depend on
those kegs to fail to run properly once built. Run `brew link` on these:
  python-packaging
  six

Description of issue

There seems to be a possible conflict between the Inkscape cask and [email protected].

Inkscape will by default use /opt/homebrew/bin/python3 as the python-interpreter for running extensions (example command and test image attached below). However, with [email protected] installed python3 points to python3.12, which does not have all necessary Python modules installed to run all Inkscape extensions.

Notably, the cssselect is missing, which is needed by a number of existing plugins, and as far as I have been able to tell, it is not really possible intended to install extra Python modules for Python3.12 at the system level, and instead users are directed to install extra packages in a virtualenv. Unfortunately, this does not seem to work for GUI applications that uses the system Python interpreter, such as Inkscape in this case. Admittedly though, I may be missing some kind of configuration option, if so, please point it out!

There is workarounds to this problem however:

The Inkscape preferences can be found in ~/Library/Application Support/org.inkscape.Inkscape/config/inkscape/preferences.xml. By changing the python-interpreter option to e.g., python3.11, Inkscape extensions will work as before:

  <group
     id="extensions"
     ...
     python-interpreter="/opt/homebrew/bin/python3.11"
     ...
/>

In theory, I believe you could also create a new virtualenv for python3 with all necessary modules and then set python-interpreter to the absolute path to that link, but I did not try that.

Supposedly, it should also be possible to change ~/.config/Inkscape/preferences.xml to:

<group
    id="extensions"
    python-interpreter="/opt/homebrew/bin/python3.11" />

This did not have any effect on my MacOS M1 machine however, but that may be a Mac/Linux difference.

I'm not entirely sure what the recommended solution is here. Obviously, Inkscape with the extensions that are available by default should really work out of the box after installation or at least, some warning should be emitted regarding this issue.
Simply installing cssselect for Python3.12 might work in the short term, but that will obviously break if a new module is added instead.

Am I missing something, or is this a real problem?

Test command-line:

inkscape --batch-process gltf_mesh_data.svg -o gltf_mesh_data.opt.svg --actions=org.inkscape.filter.embed-image.noprefs

Test Image

Relevant casks

Inkscape, [email protected]