clib `open` writes a linefeed to stdout when used in the JIT

I'm having a problem with my code generating empty lines and it appears
to be the CLib `open` function generating an empty line when used within
the JIT-VM. If I compile my program to an exe file it doesn't happen. I
also have a lot of other code running in the VM without this problem,
it's somehow particular to `open`.

A chunk of my IR that calls `open`:

defer_body_26: ; preds = %defer_end_11
  %59 = load i8*, i8** %f8686688__enc_n
  %60 = getelementptr inbounds i8, i8* %59, i64 16
  %61 = call i32 @open(i8* %60, i32 577, i32 511)
  store i32 %61, i32* %f8686688__f
  br label %defer_block_25

Where elsewhere I have `declare i32 @open(i8*, i32, i32)`.

Any ideas on what could possible be causing this?

I'm using LLVM3.8 with GCC 5.3.1 on Ubuntu 16.04.

Okay, at least it's not the execution but building causing the problem.
I'm trying to locate the precise point (maybe I have an errant print

It was my mistake. A leftover debug printing end empty line near the IR
generation code that happens to only be invoked on a function like `open`.