panicked at 'assertion failed: old_local.is_none()'

[Shihao Xia]

For given input file:

in.zip

The following code:

use starlark::eval::Evaluator;
use starlark::environment::{Module, Globals};
use starlark::values::Value;
use starlark::syntax::{AstModule, Dialect};


fn main() {
    // change filepath to the input file
    let data = std::fs::read(filepath).unwrap();
        let _  = match std::str::from_utf8(&data) {
            Ok(d) => {
                if let Ok(ast) = AstModule::parse("hello_world.star", d.to_owned(), &Dialect::Standard) {
                   
                    let globals: Globals = Globals::standard();

                    let module: Module = Module::new();

                    let mut eval: Evaluator = Evaluator::new(&module, &globals);

                    eval.eval_module(ast);  
                }

                
            },
            Err(..) => return,
        };
       
}

has output:

thread 'main' panicked at 'assertion failed: old_local.is_none()', /home/sxia/.cargo/git/checkouts/starlark-rust-59575ffdf833204c/458a203/starlark/src/eval/compiler/scope.rs:243:13
stack backtrace:
   0: rust_begin_unwind
   1: core::panicking::panic_fmt
   2: core::panicking::panic
   3: starlark::eval::compiler::scope::Scope::collect_defines_in_def
             at /home/sxia/.cargo/git/checkouts/starlark-rust-59575ffdf833204c/458a203/starlark/src/eval/compiler/scope.rs:243:13
   4: starlark::eval::compiler::scope::Scope::collect_defines_recursively_in_expr
             at /home/sxia/.cargo/git/checkouts/starlark-rust-59575ffdf833204c/458a203/starlark/src/eval/compiler/scope.rs:271:13
   5: starlark::eval::compiler::scope::Scope::collect_defines_recursively::{{closure}}
             at /home/sxia/.cargo/git/checkouts/starlark-rust-59575ffdf833204c/458a203/starlark/src/eval/compiler/scope.rs:264:34
   6: core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut
             at /home/sxia/code/rust-compiler/library/core/src/ops/function.rs:269:13
   7: starlark::syntax::uniplate::<impl starlark::syntax::ast::StmtP<P>>::visit_children_mut::{{closure}}
             at /home/sxia/.cargo/git/checkouts/starlark-rust-59575ffdf833204c/458a203/starlark/src/syntax/uniplate.rs:110:45
   8: core::iter::traits::iterator::Iterator::for_each::call::{{closure}}
             at /home/sxia/code/rust-compiler/library/core/src/iter/traits/iterator.rs:722:29
   9: core::iter::traits::iterator::Iterator::fold
             at /home/sxia/code/rust-compiler/library/core/src/iter/traits/iterator.rs:2159:21
  10: core::iter::traits::iterator::Iterator::for_each
             at /home/sxia/code/rust-compiler/library/core/src/iter/traits/iterator.rs:725:9
  11: starlark::syntax::uniplate::<impl starlark::syntax::ast::StmtP<P>>::visit_children_mut
             at /home/sxia/.cargo/git/checkouts/starlark-rust-59575ffdf833204c/458a203/starlark/src/syntax/uniplate.rs:110:17
  12: starlark::eval::compiler::scope::Scope::collect_defines_recursively
             at /home/sxia/.cargo/git/checkouts/starlark-rust-59575ffdf833204c/458a203/starlark/src/eval/compiler/scope.rs:263:9
  13: starlark::eval::compiler::scope::Scope::collect_defines_recursively::{{closure}}
             at /home/sxia/.cargo/git/checkouts/starlark-rust-59575ffdf833204c/458a203/starlark/src/eval/compiler/scope.rs:265:34
  14: core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut
             at /home/sxia/code/rust-compiler/library/core/src/ops/function.rs:269:13
  15: starlark::syntax::uniplate::<impl starlark::syntax::ast::StmtP<P>>::visit_children_mut::{{closure}}
             at /home/sxia/.cargo/git/checkouts/starlark-rust-59575ffdf833204c/458a203/starlark/src/syntax/uniplate.rs:83:65
  16: <core::slice::iter::IterMut<T> as core::iter::traits::iterator::Iterator>::for_each
             at /home/sxia/code/rust-compiler/library/core/src/slice/iter/macros.rs:211:21
  17: starlark::syntax::uniplate::<impl starlark::syntax::ast::StmtP<P>>::visit_children_mut
             at /home/sxia/.cargo/git/checkouts/starlark-rust-59575ffdf833204c/458a203/starlark/src/syntax/uniplate.rs:83:38
  18: starlark::eval::compiler::scope::Scope::collect_defines_recursively
             at /home/sxia/.cargo/git/checkouts/starlark-rust-59575ffdf833204c/458a203/starlark/src/eval/compiler/scope.rs:263:9
  19: starlark::eval::compiler::scope::Scope::enter_module
             at /home/sxia/.cargo/git/checkouts/starlark-rust-59575ffdf833204c/458a203/starlark/src/eval/compiler/scope.rs:195:9
  20: starlark::eval::<impl starlark::eval::runtime::evaluator::Evaluator>::eval_module
             at /home/sxia/.cargo/git/checkouts/starlark-rust-59575ffdf833204c/458a203/starlark/src/eval/mod.rs:98:25
...

[Neil Mitchell]

Fixed in c963048, we weren't checking for duplicate parameters to lambda, which is now sorted - thanks for the report!