lib/block-rust-go.nix

A stdenv adapter that marks Rust and Go derivations broken.

Fil-C compiles C and C++. Rust and Go bring their own compilers and runtimes, so a Fil-C build of them is either impossible or not memory safe in the Fil-C sense. With this adapter such packages fail evaluation with a "broken" problem that says why, instead of reaching a confusing error deep in rustc's or Go's platform tables. Native tools used at build time are unaffected: they come from buildPackages, whose stdenv this adapter does not touch.

Servers whose processes share memory that holds pointers are refused the same way: the PostgreSQL server here, nginx in ports.nix. Fil-C keeps each pointer's capability in the process's own shadow memory, so a pointer one process stores in shared memory has none in another (docs/nixos-userland.md). Their client libraries, such as libpq, are separate packages and stay Fil-C.

λlib, stdenvAdapters

let

19compiler=

λattrs

let

22names=

maplib.getName lib.filterlib.isDerivation attrs.nativeBuildInputs or [ ]

25isRust=

n: n ≡ "rustc" ∨ n ≡ "cargo" ∨ lib.hasSuffix"-cargo" n

attrs.pname or null ≡ "postgresql"

→

"PostgreSQL"

lib.anyisRust names ∨ attrs.cargoDeps or null ≢ null

→

"Rust"

lib.elem"go" names

→

"Go"

else

null

used by blocked

stdenvAdapters.overrideMkDerivationArgs

λold

let

39blocked=

compilerold

uses compiler used by name why

Only the problem's presence depends on the inputs, not the shape of meta: deciding the shape from nativeBuildInputs recurses.

44meta=

old.meta or { }

45problems=

old.meta.problems or { }

lib.optionalAttrsblocked ≢ null

48filc=

49kind=

"broken"

50message=

let

52name=

blocked ≡ "PostgreSQL"

→

"postgresql_${lib.versions.majorold.version}"

else

old.pname or lib.getNameold.name or "it"

uses blocked

57why=

blocked ≡ "PostgreSQL"

→

"${blocked} cannot be Fil-C: its processes share memory that holds pointers, and a Fil-C pointer's capability does not cross processes."

else

"${blocked} has no Fil-C target."

uses blocked

"${why} Take the native build instead, with filc.native = native: { inherit (native) ${name}; }; in your system's configuration, or leave it out."