Rust modules: negative default values cause build error

[bfops]

example module:

use spacetimedb::Table;

#[spacetimedb::table(accessor = foo, public)]
pub struct Foo {
    #[default(-8)]
    count: i16,
}

    stderr:    Compiling smoketest_module_fhwyysycwblss v0.1.0 (/tmp/.tmpAUgfgl)
    error[E0600]: cannot apply unary operator `-` to type `AlgebraicValue`
      --> src/lib.rs:2:1
       |
     2 | #[spacetimedb::table(accessor = defaults_test_table, public)]
       | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot apply unary operator `-`
       |
    note: `AlgebraicValue` does not implement `Neg`
      --> /home/work/SpacetimeDBPrivate/public/crates/sats/src/algebraic_value.rs:28:1
       |
    28 | pub enum AlgebraicValue {
       | ^^^^^^^^^^^^^^^^^^^^^^^ `AlgebraicValue` is defined in another crate
       = note: this error originates in the attribute macro `spacetimedb::table` (in Nightly builds, run with -Z macro-backtrace for more info)