feat(tvix/eval): Initial resolution of `<...>` paths r/5087

This commit implements (lazy) resolution of `<...>` paths via either the
NIX_PATH environment variable, or the -I command-line flag - both
handled via EvalOptions. As a result, EvalOptions can no longer derive
Copy, meaning we have to clone it at each line of the repl - this is
probably not a huge deal as repl performance is not exactly an inner
loop and we're not cloning very much.

Internally, this works by creating a thunk which pushes a constant
containing the string inside the brackets to the stack, then a new
opcode to resolve that path via the `NixPath`. To get that opcode to
work, we now have to pass in the NixPath when constructing the VM.

This (intentionally) leaves out proper implementation of path resolution
via `findFile` (cppnix just calls whatever identifier called findFile is
in scope!!!) as that's widely considered a bit of a misfeature, but if
we do decide to implement that down the road it likely wouldn't be more
than a few extra ops within the thunk introduced here.

Change-Id: Ibc979b7e425b65cbe88599940520239a4a10cee2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6918
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI

1 files changed, 1 insertions, 1 deletions

diff --git a/tvix/eval/src/main.rs b/tvix/eval/src/main.rs
index 0fbc7ad9a6..d70d82f68f 100644
--- a/tvix/eval/src/main.rs
+++ b/tvix/eval/src/main.rs
@@ -66,7 +66,7 @@ fn run_prompt(eval_options: tvix_eval::Options) {
                 }
 
                 rl.add_history_entry(&line);
-                match tvix_eval::interpret(&line, None, eval_options) {
+                match tvix_eval::interpret(&line, None, eval_options.clone()) {
                     Ok(result) => {
                         println!("=> {} :: {}", result, result.type_of());
                     }