nix-shell with data packages

[davidak]

Describe the bug
When i open a nix-shell with a packaged program, the program is available in the shell (it is in the $PATH).
But what about packages with data, like fonts?

To Reproduce

I want to test pango-view to preview a font. But i have no fonts installed.

Steps to reproduce the behavior:

1. nix run nixpkgs.pango nixpkgs.fira-code
2. search for the font:

[davidak@gaming:~]$ find / -name fira-code -print 2>/dev/null
/home/davidak/nixpkgs/pkgs/data/fonts/fira-code
/home/davidak/code/nixpkgs/pkgs/data/fonts/fira-code
/nix/store/vccsh938rxpxxvn9785vf5jbhadbgpfj-source/pkgs/data/fonts/fira-code
/nix/store/sx30vcw1cysrsbq9rdbcqladfhjb4ngx-source/pkgs/data/fonts/fira-code
/nix/store/s4b194dh5i9av3q5sc010baj40jk5m1f-opencl_pr/pkgs/data/fonts/fira-code
/nix/store/vf9y7694jgidaxg8d5j1mcgnlk5qspdw-2b417708c282d84316366f4125b00b29c49df10f.tar.gz/pkgs/data/fonts/fira-code
/nix/store/dk1x9r3q3448v3n1g40gsd6x0q9gngv9-nixos-20.03.2262.2b417708c28/nixos/pkgs/data/fonts/fira-code
/nix/store/6icrrsxyz4afd3d5iaivynb449aypnwx-nixos-20.03.2611.bb8f0cc2279/nixos/pkgs/data/fonts/fira-code
/nix/store/ixarh4adik6nnn7fc769yfnhdp5y07fg-nixos-20.09pre130979.gfedcba/nixos/pkgs/data/fonts/fira-code
/nix/store/c38b683amd74aj0qjk4d5iyq1k7aw93i-nixos-unstable-20.09pre234242.c71518e75bf/nixos-unstable/pkgs/data/fonts/fira-code
/nix/store/1pxxyqddi54ly4bnqksw5sj9hn1xcbdd-nixos-unstable-20.09pre230335.9480bae3370/nixos-unstable/pkgs/data/fonts/fira-code
/nix/store/k70za9rz3z5wq6d7ni6b5n3azgdpyklb-nixos-20.03.1950.48723f48ab9/nixos/pkgs/data/fonts/fira-code
/nix/store/bla4p2frz17sykbifsdda48i5jh6yyq7-nixos-unstable-20.09pre226148.0f5ce2fac0c/nixos-unstable/pkgs/data/fonts/fira-code
/nix/store/a5inn8qk5sa8dgc0zbb6llprcj4rw16a-nixos-20.03.2141.8b071be7512/nixos/pkgs/data/fonts/fira-code
/nix/store/s0zbwq5dzr7nc4f2n00qd5gyfrpkqm2q-nixos-20.09pre130979.gfedcba/nixos/pkgs/data/fonts/fira-code
/nix/store/bpyc413pyxbfpsbmv997k9saplq49rgb-nixos-unstable-20.09pre228622.029a5de0839/nixos-unstable/pkgs/data/fonts/fira-code
/nix/store/czc1plrs0fqx3dpb47paf62npc3lzr72-nixos-20.09pre-git/nixos/pkgs/data/fonts/fira-code

that's not the font, but nixpkgs definition of it

3. open this ticket

Expected behavior
be able to use the font in the shell

Notify maintainers

Metadata

• system: "x86_64-linux"
• host os: Linux 5.7.8, NixOS, 20.03.2611.bb8f0cc2279 (Markhor)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3.6
• channels(root): "home-manager-20.03, nixos-20.03.2611.bb8f0cc2279, nixos-hardware, nixos-unstable-20.09pre234242.c71518e75bf"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
# a list of nixos modules affected by the problem
module:

[matthewbauer]

Fontconfig requires a cache to work, so there's not an easy solution like just appending to some environment like with PATH. We could set a custom FONTCONFIG_FILE in a fontconfig setup-hook that generates a custom cache.

[FRidh]

We need a more advanced buildEnv that can, given a set of packages, determine how they should be composed.

[stale]

I marked this as stale due to inactivity. → More info

[austinbutler]

Seems a workaround has been found here: NixOS/nixpkgs#24485

[stale]

I marked this as stale due to inactivity. → More info