Compiler silently fails when output file isn't writeable.

[flysand7]

Context

• Odin: dev-2024-09:d2d202673
• OS: Windows 10 Unknown Edition (00000064) (version: 22H2), build 19045.4780
• CPU: 12th Gen Intel(R) Core(TM) i5-12500H
• RAM: 16088 MiB
• Backend: LLVM 18.1.8

Description

On windows executables are denied write operations whenever they are being executed. Therefore an attempt to overwrite the executable while it's running will fail. The problem is that whenever odin fails to write to the target executable, due to code of this executable file currently being executed, the compiler will finish compilation without errors.

Whenever a target executable is unable to be written an error message is expected from the compiler.

Reproduction

1. Compile any executable
2. Run under debugger, breakpoint anywhere
3. Compile a new executable, with modified source (it will appear to have finshed successfully)
4. Run the program in a terminal, the output doesn't change.

The compiler is expected to print errors on step 3, which it currently does not.