modular / modular/modular

[BUG] The compiler allows us to access unbound parameter of an alias

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#5,117 1 comment 0 reactions 1 assignee View on GitHub

@zyx-billy is already working on this.

Since Jul 30, 2025.

auto_priority_triaged bug modular-repo mojo
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Mojo
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Description

Bug description

As title. CC @zyx-billy.

I'm not sure whether it's intentional.

The "hole" is typed, so it's somewhat equivalent to adding a bottom value to each type in the parameter domain.

Steps to reproduce
fn main():
  alias dt = Scalar.dtype  # alias dt = ?
  alias S = SIMD[dt, 1]    # alias S = SIMD[?, 1]
System information

Mojo 25.6.0.dev2025073007 (1df3bfc1)

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