Option `--nondetstack-size-kwords=256 --small-nondetstack-size-kwords=256':
Hello world (with non-standard options).

Option `--nondet-stack-size-kwords=256 --small-nondet-stack-size-kwords=256':
Hello world (with non-standard options).

Option `--detstack-size=128 --small-detstack-size=128':
Hello world (with non-standard options).

Option `--this-is-not-a-real-option':
mercury_runtime: unrecognized option: `this-is-not-a-real-option'
The MERCURY_OPTIONS environment variable contains an invalid option.
Please refer to the Environment Variables section of the Mercury
User's Guide for details.