librsvg seems to override other gdk-pixbuf loaders

[barryfm]

Describe the bug

When I include librsvg in an configuration, it will replace gdk-pixbufs with one it generates itself. If I later include webp-pixbuf-loader, these updates to gdk-pixbuf loader path were not seen.
This maybe because librsvg was not rebuilt.

Steps To Reproduce

Steps to reproduce the behavior:

1. include librsvg in environment.systemPackages
2. rebuild
3. add webp-pixbuf-loader to environment.systemPackages
4. rebuild.

Now looking at /run/current-system/sw/lib/gdk-pixbuf-2.0/2.10.0/

1. loaders/ contains libpixbufloader-webp.so
2. loaders.cache points to /nix/store/...-libsvg-.../gdk-pixbuf-2.0/2.10.0/loaders.cache
3. loaders.cache doesn't contain any reference to webp.

I seems that since https://github.com/NixOS/nixpkgs/blob/1ecc5c7760b6961327377f2473db2538359da358/nixos/modules/services/x11/gdk-pixbuf.nix when such extensions should be able to just add themselves to
services.xserver.gdk-pixbuf.modulePackages to include themselves in the cache

In /run/current-system/sw/lib/gdk-pkgbuf-2.0/2.10.0/loaders:

loaders/libpixbufloader-svg.la:  symbolic link to /nix/store/9vn32f9zhg0v5qkxvb09bkznrkdjv6lw-librsvg-2.55.1/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-svg.la
loaders/libpixbufloader-svg.so:  symbolic link to /nix/store/9vn32f9zhg0v5qkxvb09bkznrkdjv6lw-librsvg-2.55.1/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-svg.so
loaders/libpixbufloader-webp.so: symbolic link to /nix/store/p2mk8kdma27gdljjgg830b2v90g59733-webp-pixbuf-loader-0.0.7/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-webp.so

In /run/current-system/sw/lib/gdk-pkgbuf-2.0/2.10.0/loaders.cache link:

# GdkPixbuf Image Loader Modules file
# Automatically generated file, do not edit
# Created by gdk-pixbuf-query-loaders from gdk-pixbuf-2.42.10
#
# LoaderDir = /nix/store/7h9f215fx7kgmin2k35nlkfknk701dyl-gdk-pixbuf-2.42.10/lib/gdk-pixbuf-2.0/2.10.0/loaders
#
"/nix/store/7h9f215fx7kgmin2k35nlkfknk701dyl-gdk-pixbuf-2.42.10/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-ani.so"
"ani" 4 "gdk-pixbuf" "Windows animated cursor" "LGPL"
"application/x-navi-animation" ""
"ani" ""
"RIFF    ACON" "    xxxx    " 100

"/nix/store/7h9f215fx7kgmin2k35nlkfknk701dyl-gdk-pixbuf-2.42.10/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-bmp.so"
"bmp" 5 "gdk-pixbuf" "BMP" "LGPL"
"image/bmp" "image/x-bmp" "image/x-MS-bmp" ""
"bmp" ""
"BM" "" 100

"/nix/store/7h9f215fx7kgmin2k35nlkfknk701dyl-gdk-pixbuf-2.42.10/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-gif.so"
"gif" 4 "gdk-pixbuf" "GIF" "LGPL"
"image/gif" ""
"gif" ""
"GIF8" "" 100

"/nix/store/7h9f215fx7kgmin2k35nlkfknk701dyl-gdk-pixbuf-2.42.10/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-icns.so"
"icns" 4 "gdk-pixbuf" "MacOS X icon" "GPL"
"image/x-icns" ""
"icns" ""
"icns" "" 100

"/nix/store/7h9f215fx7kgmin2k35nlkfknk701dyl-gdk-pixbuf-2.42.10/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-ico.so"
"ico" 5 "gdk-pixbuf" "Windows icon" "LGPL"
"image/x-icon" "image/x-ico" "image/x-win-bitmap" "image/vnd.microsoft.icon" "application/ico" "image/ico" "image/icon" "text/ico" ""
"ico" "cur" ""
"  \001   " "zz znz" 100
"  \002   " "zz znz" 100

"/nix/store/7h9f215fx7kgmin2k35nlkfknk701dyl-gdk-pixbuf-2.42.10/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-pnm.so"
"pnm" 4 "gdk-pixbuf" "PNM/PBM/PGM/PPM" "LGPL"
"image/x-portable-anymap" "image/x-portable-bitmap" "image/x-portable-graymap" "image/x-portable-pixmap" ""
"pnm" "pbm" "pgm" "ppm" ""
"P1" "" 100
"P2" "" 100
"P3" "" 100
"P4" "" 100
"P5" "" 100
"P6" "" 100

"/nix/store/7h9f215fx7kgmin2k35nlkfknk701dyl-gdk-pixbuf-2.42.10/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-qtif.so"
"qtif" 4 "gdk-pixbuf" "QuickTime" "LGPL"
"image/x-quicktime" "image/qtif" ""
"qtif" "qif" ""
"abcdidsc" "xxxx    " 100
"abcdidat" "xxxx    " 100

"/nix/store/7h9f215fx7kgmin2k35nlkfknk701dyl-gdk-pixbuf-2.42.10/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-tga.so"
"tga" 4 "gdk-pixbuf" "Targa" "LGPL"
"image/x-tga" ""
"tga" "targa" ""
" \001\001" "x  " 100
" \001\t" "x  " 100
"  \002" "xz " 99
"  \003" "xz " 100
"  \n" "xz " 100
"  \v" "xz " 100

"/nix/store/7h9f215fx7kgmin2k35nlkfknk701dyl-gdk-pixbuf-2.42.10/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-tiff.so"
"tiff" 5 "gdk-pixbuf" "TIFF" "LGPL"
"image/tiff" ""
"tiff" "tif" ""
"MM *" "  z " 100
"II* " "   z" 100
"II* \020   CR\002 " "   z zzz   z" 0

"/nix/store/7h9f215fx7kgmin2k35nlkfknk701dyl-gdk-pixbuf-2.42.10/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-xbm.so"
"xbm" 4 "gdk-pixbuf" "XBM" "LGPL"
"image/x-xbitmap" ""
"xbm" ""
"#define " "" 100
"/*" "" 50

"/nix/store/7h9f215fx7kgmin2k35nlkfknk701dyl-gdk-pixbuf-2.42.10/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-xpm.so"
"xpm" 4 "gdk-pixbuf" "XPM" "LGPL"
"image/x-xpixmap" ""
"xpm" ""
"/* XPM */" "" 100

# GdkPixbuf Image Loader Modules file
# Automatically generated file, do not edit
# Created by gdk-pixbuf-query-loaders from gdk-pixbuf-2.42.10
#
# LoaderDir = /nix/store/9vn32f9zhg0v5qkxvb09bkznrkdjv6lw-librsvg-2.55.1/lib/gdk-pixbuf-2.0/2.10.0/loaders
#
"/nix/store/9vn32f9zhg0v5qkxvb09bkznrkdjv6lw-librsvg-2.55.1/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-svg.so"
"svg" 6 "gdk-pixbuf" "Scalable Vector Graphics" "LGPL"
"image/svg+xml" "image/svg" "image/svg-xml" "image/vnd.adobe.svg+xml" "text/xml-svg" "image/svg+xml-compressed" ""
"svg" "svgz" "svg.gz" ""
" <svg" "*    " 100
" <!DOCTYPE svg" "*             " 100

Notify maintainers

Not sure how to include team.gnome.members? @GNOME

Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

 - system: `"x86_64-linux"`
 - host os: `Linux 6.2.5, NixOS, 23.05 (Stoat), 23.05.20230313.8e3fad8`
 - multi-user?: `no`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.13.3`
 - channels(root): `""`
 - channels(barry): `""`
 - nixpkgs: `not found`

This is from a nix flakes rebuild using flake:nixpkgs

[barryfm]

It seems /etc/set-environment sets up GDK_PIXBUF_MODULE_FILE to a properly generated /nix/store/qq618cwqfs0v81lin9l26c0pfccphw49-gdk-pixbuf-loaders.cache.

But gnome-terminal and gnome-console override the environment variable
and use /nix/store/9vn32f9zhg0v5qkxvb09bkznrkdjv6lw-librsvg-2.55.1/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache in their executables.

But if I use foot or xterm I get the proper GDK_PIXBUF_MODULE_FILE setup.

Could librsvg and all the packages that explicitlly do: wrapProgram ... --set GDK_PIXBUF_MODULE_FILE "${librsvg.out}/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache" be fixed.

I don't think what plugins to gdk-pixbuf are available is something that a package should limit. Even in a pure environment, the selection of paths should be inclusive of all the plugins added to the environment or explicitly an input to any of the packages in that environment.

[Artturin]

I reckon changing this

nixpkgs/pkgs/build-support/setup-hooks/wrap-gapps-hook/wrap-gapps-hook.sh

Line 14 in a9afcd2

gappsWrapperArgs+=(--set GDK_PIXBUF_MODULE_FILE "$GDK_PIXBUF_MODULE_FILE")

to --set-default would help but may cause other issues (like #54278)