nix-olde - find outdated NixOS packages

January 19, 2023


I wrote a nix-olde tool to print outdated packages on your NixOS system. Run it as:

$ git clone
$ cd nix-olde
$ cargo build && target/debug/nix-olde
Fetching 'installed' ...
Fetching 'repology' ...
Fetching 'available' ...
... 'available' done.
... 'installed' done.
... 'repology' done.
repology a52dec "0.8.0" | nixpkgs {"0.7.4"} {"nixos.a52dec"}
repology alsa-lib "1.2.8" | nixpkgs {""} {"nixos.alsa-lib"}
repology xterm "378" | nixpkgs {"377"} {"nixos.xterm"}
repology xz "5.4.1" | nixpkgs {"5.4.0"} {"nixos.xz"}
repology zxing-cpp-nu-book "2.0.0" | nixpkgs {"1.4.0"} {"nixos.zxing-cpp"}

Here we see all sorts of packages outdated in nixpkgs along with their versions and versions known to database and a package attribute name.

I wrote it for the purpose of tricking you (and myself) to send pull requests against nixpkgs to update some of those outdated packages :). Most of the time there is no major reason why a specific package is outdated.

More words

A while ago I shared a set of hacks I use to get a list of outdated packages. My system has ~1550 packages. How many of them are actually outdated? Let’s compare that hack with nix-olde result.

The hack looked good enough to catch packages with simple naming scheme that patches upstream, nixpkgs and repology. It returned 240 packages (about 15%). It’s quite a lot. I would expect not that many.

Moreover, some packages never got into the list: none of python, perl or haskell are in the report either. I skimmed through all outdated nix unstable package known to repology and found a few python and haskell I use. Not good.

nix-olde improvements

My hack clearly failed to map some of packages back to repology names. If I could just print unmapped packages maybe it would be a good starting point to see what I fail to cover. Thus the tool’s idea was born.

The idea was simple:

Having looked at list of available packages I realized it’s exactly the source nixpkgs uses to tell repology what’s in nixpkgs! It’s hidden in make-tarball.nix:

echo -n '{"version":2,"packages":' > tmp
nix-env -f . -I nixpkgs=$src -qa --meta --json --arg config 'import ${./packages-config.nix}' >> tmp
echo -n '}'

Here we extract metadata around <nixpkgs> attributes by passing a special config that untangles metadata from current system.

Thus, the mapping from installed to available packages is trivial using the same technique and the same output data.

With help of serde rust crate I was able to get a trivial json reader in 2 lines of code.

nix-olde reports 391 outdated package (151 more, or about 25% of packages). That is a substantial improvement over a hack. New additions are mainly python and perl packages.

As a bonus with --verbose flag I can see now what packages fail to map an attribute to repology database:

$ ./mkrun.bash -n ~/n --verbose
Installed packages missing in available list: ["antlr-runtime-cpp-4.9.3",
"binutils-patchelfed-ld-2.40", "binutils-patchelfed-ld-wrapper-2.40",
"boost-build-boost-1.79.0", "bootstrap-stage0-binutils-wrapper-",
"bootstrap-stage0-glibc-bootstrap", "bootstrap-stage1-gcc-wrapper-",
"bootstrap-stage2-gcc-wrapper-", "bootstrap-stage3-gcc-wrapper-",
"bootstrap-stage4-gcc-wrapper-13.0.0", "cargo-bootstrap-1.65.0",
"catalog-legacy-uris.patch", "compiler-rt-static-wasm32-unknown-wasi-12.0.1",
"d3-flame-graph-templates-4.1.3", "dejavu-fonts-full-2.37",
"dejavu-fonts-minimal-2.37", "eglexternalplatform-1.1", "gfortran-13.0.0",
"gmp-with-cxx-stage3-6.2.1", "gmp-with-cxx-stage4-6.2.1",
"i686-w64-mingw32-binutils-2.40", "i686-w64-mingw32-binutils-wrapper-2.40",
"i686-w64-mingw32-stage-static-gcc-wrapper-13.0.0", "isl-stage3-0.20",
"libcxxabi-static-wasm32-unknown-wasi-12.0.1", "libmpc-stage3-1.3.1",
"linux-config-6.1.6", "linux-headers-static-6.1",
"mcfgthreads-i686-w64-mingw32-git", "mcfgthreads-x86_64-w64-mingw32-git",
"mingw-w64-i686-w64-mingw32-10.0.0", "mingw-w64-x86_64-w64-mingw32-10.0.0",
"mpfr-stage3-4.2.0", "musl-static-x86_64-unknown-linux-musl-1.2.3",
"nixos-version", "nss-cacert-certdata-3.86",
"rakshasa-libtorrent-0.13.8+date=2021-08-07", "ruby2.7.6-msgpack-1.5.1",
"ruby2.7.6-neovim-0.9.0", "rubygems-3.3.20", "rustc-bootstrap-1.65.0",
"rustfmt-nightly-1.66.1", "systemtap-4.5", "texlive-bin-2022",
"texlive-core-big.bin-2022", "vkd3d-1.5", "wasilibc-static-wasm32-unknown-wasi-17",
"x86_64-w64-mingw32-binutils-2.40", "x86_64-w64-mingw32-binutils-wrapper-2.40",

Entries like bootstrap-stage3-gcc-wrapper are not very interesting: they are synthetic packages built for bootstrap and should be an alias to a nixpkgs-specific shell wrapper. I’ll try to filter them out by default.

Entries like gfortran are nixpkgs-specific forms of gcc. It would be nice to somehow alias those back to gcc as well. Maybe we should provide a bit of extra fields in meta section of nixpkgs package descriptions to make it machine-generated.

Entries like xmms2 are the packages from my local overlays. It is expected to be in the list.

Entries like systemtap look like a mapping bug. Needs more investigation. At least these are a minority and are easily debuggable to make nix-olde better reflect.

Parting words

nix-olde was the first non-trivial program I wrote in rust. The experience is very pleasant: option parsing and json parsing is trivial, data types are naive and yet good enough to get the job done.

nixpkgs has quite a few outdated packages in base install for my desktop system: around 25%. Worth improving individual packages and extending them to add auto-update scripts for r-ryantm to help humans in this task.

Have fun!