openmoji has started taking forever to build.

[kevincox]

Describe the bug

openmoji-color and openmoji-black now both take >12h to build. They are timing out on hydra https://hydra.nixos.org/job/nixos/trunk-combined/nixpkgs.openmoji-color.x86_64-linux.

Steps To Reproduce

Steps to reproduce the behavior:

1. nix-build -A openmoji-color

Notify maintainers

@fgaz

[fgaz]

Could this be the same as #97871? Should we switch to prebuilt fonts here too?

[kevincox]

It could be. But in the past the build only took a minute or 2. Now it takes basically forever. I'm trying to bisect when this was introduced but bisecting timeouts is slow and error-prone.

[kevincox]

I did a better bisection and got 69da642 (#163439) which is much more helpful. I saw that PR but thought it seemed too old. I guess I forgot how long a staging cycle can take.

cc @evils @jtojnar @erictapen

I don't know what the best approach here is. Report the bug upstream to fontforge or openmoji? There are a lot of warnings and errors in the build so I suspect that it may be an openmoji problem and fontforge was doing its best before and working but now is failing?

The command I used for reference was:

git bisect run zsh -c 'set -x; nix build -f . openmoji-color --max-silent-time 600 |& tee /tmp/out; [[ $pipestatus[1] == 0 ]] && exit 0; grep -- "-openmoji-.*timed out after .* seconds of silence" /tmp/out && exit 1; exit 125'

[evils]

after a brief look at this
fontforge has a reported regression in its ability to remove overlaps (fontforge/fontforge#4859)
but if openmoji is the only font that is failing because of that, maybe they're relying too much on fontforge's abliity to fix things at build time

(with the latest master commits from openmoji and fontforge, the openmoji build also hangs)

[kevincox]

I tried diffing the logs but they are basically completely different once scfbuild starts. In case they are helpful to anyone here are the builds before and after that commit. (The after obviously cuts off after the "infinite loop").

before.log
after.log

[fgaz]

Great investigation!

Maybe as a short-term fix we could override fontforge for this package?

[kevincox]

That sounds like a reasonable mitigation until a patch is available.

[OPNA2608]

Bump, would really love to have openmoji available when I upgrade 21.11 -> 22.05!

[fgaz]

@kevincox why the thumbs down?

[kevincox]

Bumping issues is not a helpful thing to do.

[fgaz]

In general yes, though in this case it reminded me to fix this before 22.05 :)

Here you go @OPNA2608: #174795

[jtojnar]

I tried running bisection on fontforge itself using nix-bisect after applying the patch below:

$ git bisect start 20220308 20201107
$ extra-bisect run \
  nix-build-status \
    --option max-silent-time 240 \
    -f ~/Projects/nixpkgs \
    openmoji-color

Unfortunately, the automatic bisection did not work for some reason. Possibly because the timeout regex does not match the error message: error: building of '/nix/store/6z3q2pb6frq47ch617nayaambb7rsyxa-openmoji-13.1.0.drv!out' from .drv file timed out after 240 seconds of silence

--- a/pkgs/data/fonts/openmoji/default.nix
+++ b/pkgs/data/fonts/openmoji/default.nix
@@ -3,6 +3,10 @@
 , fetchFromGitHub
 , scfbuild
 , nodejs
+, fontforge
+, libuninameslist
+, fetchpatch
+, patch
 , nodePackages
 , python3Packages
 , variant ? "color" # "color" or "black"
@@ -14,6 +18,30 @@ let
     [ "OpenMoji-Color.ttf" "OpenMoji-Black.ttf" ]
     variant;
 
+    fontforge-bisect = fontforge.overrideAttrs (old: rec {
+      version = "bisect";
+      src = /home/jtojnar/Projects/fontforge;
+      patches = [
+        (fetchpatch {
+          url = "https://salsa.debian.org/fonts-team/fontforge/raw/76bffe6ccf8ab20a0c81476a80a87ad245e2fd1c/debian/patches/0001-add-extra-cmake-install-rules.patch";
+          sha256 = "u3D9od2xLECNEHhZ+8dkuv9818tPkdP6y/Tvd9CADJg=";
+        })
+        # (fetchpatch {
+        #   url = "https://github.com/fontforge/fontforge/commit/69e263b2aff29ad22f97f13935cfa97a1eabf207";
+        #   sha256 = "06yyf90605aq6ppfiz83mqkdmnaq5418axp9jgsjyjq78b00xb29";
+        # })
+      ];
+      prePatch = ''
+        patch() {
+          ${patch}/bin/patch "$@"  || echo 'Failed to apply patch, continuing'
+        }
+      '';
+      buildInputs = old.buildInputs ++ [ libuninameslist ];
+    });
+    scfbuild-with-fontforge-bisect = scfbuild.override (old: {
+      fontforge = fontforge-bisect;
+    });
+
 in stdenv.mkDerivation rec {
   pname = "openmoji";
   version = "13.1.0";
@@ -26,7 +54,7 @@ in stdenv.mkDerivation rec {
   };
 
   nativeBuildInputs = [
-    scfbuild
+    scfbuild-with-fontforge-bisect
     nodejs
     nodePackages.glob
     nodePackages.lodash

[Artturin]

needs to be reported upstream

[fgaz]

Which one though? Openmoji or fontforge?