Script calling with parameter for ion results in ion only evaluating the parameter and quiting the script
Defer ion parameters [program or path name shall never start with - or -- (otherwise it gets messy to parse/decide)]
Case 1: If most leftward argument is ion option, only valid ion options may follow or error.
Case 2: If not, defer evaluation to use explicit statement (later to be specified).
Other solution would explicitly check all most leftward arguments ever to evaluate for shell option, which looks inefficient.
#!/usr/bin/env ion
echo 'test'
called by
# ./test.sh --version
result:
ion 1.0.0-alpha (x86_64-unknown-linux-gnu)
rev a5fb10c7