var=value, not set ...set var=42
set var 42var=42set is not used to set or assign variables in Bourne
shells. It's used to set shell options and positional parameters.
To assign variables, use var=value with no
set or other qualifiers.
If you actually do want to set positional parameters, simply quoting
them or using -- will make shellcheck stop warning, e.g.
set -- var1 var2 or set "foo=bar".
ShellCheck is a static analysis tool for shell scripts. This page is part of its documentation.