A non-constant value was used in a constant expression.
Erroneous code example:
let foo = 42;
let a: [u8; foo]; // error: attempt to use a non-constant value in a constant‘constant’ means ‘a compile-time value’.
More details can be found in the Variables and Mutability section of the book.
To fix this error, please replace the value with a constant. Example:
let a: [u8; 42]; // ok!Or:
const FOO: usize = 42;
let a: [u8; FOO]; // ok!