Unfortunately, the `||` iterator always prefixes by `#pragma omp`. With your example up there you get `#pragma omp acc kernels` above the annotated loop.
I can only assume that it _[should](https://forum.nim-lang.org/postActivity.xml#should) be a relatively straightforward compiler fix to make that adjustable / only default to `#pragma omp` if the given string doesn't start with `#pragma` though (the `||` iterator came up multiple lately for me and there's quite a few quality improvements it could use).
