Assembler terminates without error message

[pol-rivero]

I found a small bug on the latest version 0.11.3. Let's say I want to assemble the following code:

#subruledef REG {
    my_reg => 0xA
}
#ruledef {
    test {Addr: u16} => 0x1 @ Addr
    test {register: REG} + {Not_Imm: u16} => register`4 @ Imm
}

test my_reg + 1

Version 0.11.2 succesfully identifies that I was trying to use the second instruction (test {register: REG} + {Not_Imm: u16}), and that I had made a typo (I typed Not_Imm: u16 instead of Imm: u16). Therefore, it correcly displays the error message

error: unknown variable
test {register: REG} + {Not_Imm: u16} => register`4 @ Imm
                                                      ^^^

However, version 0.11.3 doesn't show any error message and just terminates with exit code 1. Its only output is

customasm v0.11.3 (2020-12-05, x86_64-pc-windows-gnu)
assembling `test.asm`...

Again, it's a pretty small bug that only happens on this edge case, but it's rather confusing to not have any indication on what went wrong, specially when assembling large files.

[clubby789]

Tracked the problem down to

customasm/src/diagn/report.rs

Lines 242 to 249 in 030ed10

	pub fn print_all(&self, writer: &mut dyn Write, fileserver: &dyn FileServer)
	{
	for msg in &self.messages
	{
	self.print_msg(writer, fileserver, msg, 0);
	writeln!(writer).unwrap();
	}
	}

The for loop isn't run at all. Printing the length of report.messages every time a new message is pushed outputs '1' several times, so somewhere the messages seem to be getting lost.