Windows: with node-canvas, "cannot register existing type 'PangoCairoFontMap'"

[laurieherault]

Are you using the latest version? Is the version currently in use as reported by npm ls sharp the same as the latest version as reported by npm view sharp dist-tags.latest?
Yes (0.27.0)

What are the steps to reproduce?

• Install Sharp 0.27.0 on Windows 10
• Convert SVG with text to PNG
• Error :

Fontconfig error: Cannot load default config file

(sharp:6452): GLib-GObject-WARNING **: 17:17:43.297: cannot register existing type 'PangoFontMap'

(sharp:6452): GLib-GObject-WARNING **: 17:17:43.298: cannot add private field to invalid (non-instantiatable) type '<invalid>'

(sharp:6452): GLib-GObject-CRITICAL **: 17:17:43.298: g_type_add_interface_static: assertion 'G_TYPE_IS_INSTANTIATABLE (instance_type)' failed

(sharp:6452): GLib-CRITICAL **: 17:17:43.298: g_once_init_leave: assertion 'result != 0' failed

(sharp:6452): GLib-GObject-CRITICAL **: 17:17:43.299: g_type_register_static: assertion 'parent_type > 0' failed

(sharp:6452): GLib-GObject-WARNING **: 17:17:43.299: cannot add private field to invalid (non-instantiatable) type '<invalid>'

(sharp:6452): GLib-GObject-CRITICAL **: 17:17:43.299: g_type_add_interface_static: assertion 'G_TYPE_IS_INSTANTIATABLE (instance_type)' failed

(sharp:6452): GLib-CRITICAL **: 17:17:43.299: g_once_init_leave: assertion 'result != 0' failed

(sharp:6452): GLib-GObject-CRITICAL **: 17:17:43.299: g_type_register_static: assertion 'parent_type > 0' failed

(sharp:6452): GLib-GObject-WARNING **: 17:17:43.299: cannot register existing type 'PangoCairoFontMap'

More information

• It's work well with Sharp 0.25.4 on Windows 10 or Sharp 0.27.0 on Linux
• The problem start with v0.26.0

What is the expected behaviour?
Generate a PNG from SVG

Are you able to provide a minimal, standalone code sample, without other dependencies, that demonstrates this problem?

  const test = `
  <svg width="200" height="250" version="1.1" xmlns="http://www.w3.org/2000/svg">
    <text x="10" y="10">
      Hi !
    </text>
  </svg>`;

  const data1 = await sharp(Buffer.from(test), { density: 72 })
    .png()
    .toBuffer();

Are you able to provide a sample image that helps explain the problem?
No

What is the output of running npx envinfo --binaries --system?
System:
OS: Windows 10 10.0.19042
CPU: (16) x64 Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz
Memory: 3.36 GB / 15.93 GB
Binaries:
Node: 14.15.1 - C:\Program Files\nodejs\node.EXE
npm: 6.13.7 - C:\Program Files\nodejs\npm.CMD

[lovell]

Hi, thanks for reporting, are you sure v0.26.0 is similarly broken? I think this relates to #2515, which only affects v0.27.0.

[laurieherault]

Hi,
Thanks for your fast answer!

But I opened an issue too quickly (Sorry....). My example is incomplete. The problem comes from an incompatibility with node-canvas once it is used (and not just loaded).

Yes we have problème with 0.26.0 and 0.27.0. The 0.25.4 work.

const sharp = require('sharp');
const { createCanvas } = require("canvas");

async function test() {
  // We use node-canvas for measure text width for the SVG generation
  const canvas = createCanvas(600, 60);
  const ctx = canvas.getContext("2d"); 

  const test = `<svg width="200" height="250" version="1.1" xmlns="http://www.w3.org/2000/svg">
    <text x="10" y="10">
      Hi !
    </text>
  </svg>`;

  // When we transform the SVG to PNG we have a bug
  const data1 = await sharp(Buffer.from(test), { density: 72 })
    .png()
    .toBuffer();
  console.log(data1);
}

test();

[lovell]

Does setting the PANGOCAIRO_BACKEND="win32" environment variable help?

[laurieherault]

I have another error with PANGOCAIRO_BACKEND="win32" :

Pango-ERROR **: 20:37:16.763: Unknown $PANGOCAIRO_BACKEND value.
  Available backends are: fontconfig

[lovell]

Thanks for checking, the only other quick fix I can think of is to alter the order in which sharp and canvas are required.

Since v0.26.0 of sharp, the prebuilt shared library we provide is statically-linked to help avoid conflict with other native modules.

The prebuilt binaries provided by canvas are all dynamically-linked DLLs, some of which are for rather old versions of the dependencies - see https://github.com/node-gfx/node-canvas-prebuilt - perhaps ask if they would be willing/able to either update or provide a single statically-linked DLL?

[laurieherault]

We decided not to use node-canvas anymore. It's easier :)
Thank you !