Unfortunately you will need to raise an issue with the developer of SublimeInput to add the ability to do this.
Inline errors are powered by the system that captures the output of builds to allow you to navigate between error messages. Normally that would be the
exec command from the
Default package in conjunction with some build system options that tell Sublime how to recognize messages that indicate where errors are located.
The SublimeInput package doesn't use a build system in order to execute the program. Additionally the command that it implements that does run your program for you is a copy of the
exec command that doesn't include the extra functionality for powering inline errors at all.
Thus in order to support this the command in the package would need to be enhanced to replicate what the
exec command is doing. Also the configuration would need to include extra settings to tell it how the different languages recognize errors.