LLVM error when function returns !?[]u8 as !?[]const u8

[ghost]

fn inner() !?[]u8 {
    return error.Damn;
}

fn outer() !?[]const u8 {
    return inner();
}

pub fn main() void {
    _ = outer() catch {};
}

broken LLVM module found: Call parameter type does not match function signature!
{ %"?[]const u8", i16 }* %0
 { %"?[]u8", i16 }*  call fastcc void @inner({ %"?[]const u8", i16 }* sret %0, %std.builtin.StackTrace* %1), !dbg !1050

This is a bug in the Zig compiler.
Unable to dump stack trace: debug info stripped
Abort trap: 6

It works if both functions return the same type (both const or both non-const).

If it's reversed so that inner returns !?[]const u8 and outer returns !?[]u8, it correctly gives a compile error.

I think my code should compile. It works if I add a redundant try in the return statement.

[daurnimator]

(error still exists on master)