385c797884
Unary operator applications are thunked which can easily be observed by
nix-instantiate --eval -E '[ (!true) (-1) ]'
Unfortunately, there are few simple expressions where this makes a
difference in the end result. Thus it only cropped up when using nixpkgs
for cross compilation: Here we would compile the expression
!(stdenv.cc.isGNU or false)
to assemble python3Minimal's passthru attribute set (at least this seems
to be the most likely explanation from the backtraces I've studied).
This means that an unthunked
<stdenv.cc.isGNU or false>
OpForce
OpInvert
would be performed in order to assemble this attribute set, causing
stdenv.cc to be evaluated too early, causing an infinite recursion.
Resolves b/273.
It seems that having a test suite that doesn't use --strict and relies
on thunks rendered as <CODE> would be beneficial for catching such
issues. I've not been able to find a test case with --strict that
demonstrates the problem fixed in this CL.
Change-Id: I640a5827b963f5b9d0f86fa2142e75e3a6bbee78
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8654
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
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|---|---|---|
| .. | ||
| benches | ||
| builtin-macros | ||
| docs | ||
| proptest-regressions/value | ||
| src | ||
| tests | ||
| .skip-subtree | ||
| build.rs | ||
| Cargo.toml | ||
| default.nix | ||
| README.md | ||
Tvix Evaluator
This project implements an interpreter for the Nix programming language. You can experiment with an online version of the evaluator: tvixbolt.
The interpreter aims to be compatible with nixpkgs, on the
foundation of Nix 2.3.
Important note: The evaluator is not yet feature-complete, and while the core mechanisms (compiler, runtime, ...) have stabilised somewhat, a lot of components are still changing rapidly.
Please contact TVL with any questions you might have.
Building tvix-eval
Please check the README.md one level up for instructions on how to build this.
The evaluator itself can also be built with standard Rust tooling (i.e. cargo build).
If you would like to clone only the evaluator and build it directly with Rust tooling, you can do:
git clone https://code.tvl.fyi/depot.git:/tvix/eval.git tvix-eval
cd tvix-eval && cargo build
Nix test suite
C++ Nix implements a language test suite in the form of Nix source code files, and their expected output. The coverage of this test suite is not complete, but we intend to be compatible with it.
We have ported the test suite to Tvix, but do not run it by default as we are not yet compatible with it.
You can run the test suite by enabling the nix_tests feature in
Cargo:
cargo test --features nix_tests
rnix-parser
Tvix is written in memory of jD91mZM2, the author of rnix-parser who sadly passed away.
Tvix makes heavy use of rnix-parser in its bytecode compiler. The parser is now maintained by Nix community members.