Warning: This program is experimental and its interface is subject to change.
nix why-depends - show why a package has another package in its closure
nix why-depends [option...] package dependency
Show one path through the dependency graph leading from Hello to Glibc:
# nix why-depends nixpkgs#hello nixpkgs#glibc /nix/store/v5sv61sszx301i0x6xysaqzla09nksnd-hello-2.10 └───bin/hello: …...................../nix/store/9l06v7fc38c1x3r2iydl15ksgz0ysb82-glibc-2.32/lib/ld-linux-x86-64.… → /nix/store/9l06v7fc38c1x3r2iydl15ksgz0ysb82-glibc-2.32
Show all files and paths in the dependency graph leading from Thunderbird to libX11:
# nix why-depends --all nixpkgs#thunderbird nixpkgs#xorg.libX11 /nix/store/qfc8729nzpdln1h0hvi1ziclsl3m84sr-thunderbird-78.5.1 ├───lib/thunderbird/libxul.so: …6wrw-libxcb-1.14/lib:/nix/store/adzfjjh8w25vdr0xdx9x16ah4f5rqrw5-libX11-1.7.0/lib:/nix/store/ssf… │ → /nix/store/adzfjjh8w25vdr0xdx9x16ah4f5rqrw5-libX11-1.7.0 ├───lib/thunderbird/libxul.so: …pxyc-libXt-1.2.0/lib:/nix/store/1qj29ipxl2fyi2b13l39hdircq17gnk0-libXdamage-1.1.5/lib:/nix/store… │ → /nix/store/1qj29ipxl2fyi2b13l39hdircq17gnk0-libXdamage-1.1.5 │ ├───lib/libXdamage.so.1.1.0: …-libXfixes-5.0.3/lib:/nix/store/adzfjjh8w25vdr0xdx9x16ah4f5rqrw5-libX11-1.7.0/lib:/nix/store/9l0… │ │ → /nix/store/adzfjjh8w25vdr0xdx9x16ah4f5rqrw5-libX11-1.7.0 …
Show why Glibc depends on itself:
# nix why-depends nixpkgs#glibc nixpkgs#glibc /nix/store/9df65igwjmf2wbw0gbrrgair6piqjgmi-glibc-2.31 └───lib/ld-2.31.so: …che Do not use /nix/store/9df65igwjmf2wbw0gbrrgair6piqjgmi-glibc-2.31/etc/ld.so.cache. --… → /nix/store/9df65igwjmf2wbw0gbrrgair6piqjgmi-glibc-2.31
Show why Geeqie has a build-time dependency on
# nix why-depends --derivation nixpkgs#geeqie nixpkgs#systemd /nix/store/drrpq2fqlrbj98bmazrnww7hm1in3wgj-geeqie-1.4.drv └───/: …atch.drv",["out"]),("/nix/store/qzh8dyq3lfbk3i1acbp7x9wh3il2imiv-gtk+3-3.24.21.drv",["dev"]),("/… → /nix/store/qzh8dyq3lfbk3i1acbp7x9wh3il2imiv-gtk+3-3.24.21.drv └───/: …16.0.drv",["dev"]),("/nix/store/8kp79fyslf3z4m3dpvlh6w46iaadz5c2-cups-2.3.3.drv",["dev"]),("/nix… → /nix/store/8kp79fyslf3z4m3dpvlh6w46iaadz5c2-cups-2.3.3.drv └───/: ….3.1.drv",["out"]),("/nix/store/yd3ihapyi5wbz1kjacq9dbkaq5v5hqjg-systemd-246.4.drv",["dev"]),("/… → /nix/store/yd3ihapyi5wbz1kjacq9dbkaq5v5hqjg-systemd-246.4.drv
Nix automatically determines potential runtime dependencies between
store paths by scanning for the hash parts of store paths. For
instance, if there exists a store path
/nix/store/9df65igwjmf2wbw0gbrrgair6piqjgmi-glibc-2.31, and a file
inside another store path contains the string
9df65igw…, then the
latter store path refers to the former, and thus might need it at
runtime. Nix always maintains the existence of the transitive closure
of a store path under the references relationship; it is therefore not
possible to install a store path without having all of its references
Sometimes Nix packages end up with unexpected runtime dependencies; for instance, a reference to a compiler might accidentally end up in a binary, causing the former to be in the latter's closure. This kind of closure size bloat is undesirable.
nix why-depends allows you to diagnose the cause of such issues. It
shows why the store path package depends on the store path
dependency, by showing a shortest sequence in the references graph
from the former to the latter. Also, for each node along this path, it
shows a file fragment containing a reference to the next store path in
To show why derivation package has a build-time rather than runtime
dependency on derivation dependency, use
Show all edges in the dependency graph leading from package to dependency, rather than just a shortest path.
For each edge in the dependency graph, show the files in the parent that cause the dependency.
Common evaluation options:
Pass the value expr as the argument name to Nix functions.
Pass the string string as the argument name to Nix functions.
The Nix store to use for evaluations.
Allow access to mutable paths and repositories.
Add path to the list of locations used to look up
Override the flake registries, redirecting original-ref to resolved-ref.
Common flake-related options:
Commit changes to the flake's lock file.
Use the inputs of the specified flake as registry entries.
Don't allow lookups in the flake registries. This option is deprecated; use
Do not allow any updates to the flake's lock file.
Do not write the flake's newly generated lock file.
Override a specific flake input (e.g.
dwarffs/nixpkgs). This implies
Recreate the flake's lock file from scratch.
Update a specific flake input (ignoring its previous entry in the lock file).
Options that change the interpretation of installables:
Operate on the store derivation rather than its outputs.
Interpret installables as attribute paths relative to the Nix expression expr.
Interpret installables as attribute paths relative to the Nix expression stored in file. If file is the character -, then a Nix expression will be read from standard input.