5.9 KiB
hnix
Haskell parser, evaluator and type checker for the Nix language.
Contents
CI | |
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Prerequisites
Until hnix-store
is ready, nix-store
is still used for interacting with the store paths, so Nix is still required installed and available through $PATH
.
Getting Started
git clone --recursive https://github.com/haskell-nix/hnix.git
cd hnix
nix-shell
cabal v2-configure --enable-tests
cabal v2-build
Run testing:
-
Default:
cabal v2-test
-
All:
env ALL_TESTS=yes cabal v2-test
-
Selected (list of tests is in
tests/Main.hs
):env NIXPKGS_TESTS=yes PRETTY_TESTS=1 cabal v2-test
Run built binary with Cabal (--
is for separation between cabal
& hnix
args):
cabal v2-run hnix -- --help
Using the REPL
Enter REPL:
hnix --repl
To evaluate an expression and make it available in the REPL as the input
variable use:
hnix --eval -E '(import <nixpkgs> {}).pkgs.hello' --repl
Use the :help
command for a list of all available REPL commands.
Cachix prebuild binary caches
To autoload prebuild project dependencies - please, enable the official HNix Cachix binary cache:
-
Go through https://cachix.org/ and set it up.
-
Run:
cachix use hnix
Building
With benchmarks
To build hnix
with benchmarks enabled:
nix-shell
cabal v2-configure --enable-tests --enable-benchmarks
cabal v2-build
cabal v2-bench
With profiling
To build hnix
with profiling enabled:
nix-shell
cabal v2-configure --enable-tests --enable-profiling --flags=profiling
cabal v2-build
cabal v2-run hnix -- <args> +RTS -p
With full debug info
To build hnix
for debugging, with full tracing output and stack traces:
nix-shell
cabal v2-configure --enable-tests --enable-profiling --flags=profiling --flags=tracing
cabal v2-build
cabal v2-run hnix -- -v5 --trace <args> +RTS -xc
Note that this will run quite slowly, but will give the most information as to what might potentially be going wrong during parsing or evaluation.
Contributing
-
If something in the quests looks interesting, look through the thread and leave a comment taking it, to let others know you're working on it.
-
You are free to chat with everyone on Gitter.
-
When pull request is ready to be submitted, to save time - please, test it with:
git submodule update --init --recursive
nix-shell --run "LANGUAGE_TESTS=yes cabal v2-test"
Please, check that all tests that were passing prior (most probably all tests mentioned in the command) are still passing for the PR, it is faster to chech that locally then through CI. It's OK if no new tests are passing.
Evaluating Nixpkgs with HNix
Currently the main high-level goal is to be able to evaluate all of Nixpkgs. To run this yourself, first build hnix
with nix-build
, then run the following command:
./result/bin/hnix --eval -E "import <nixpkgs> {}" --find