Problem perl script

Running this perl script with Perl and one line gives a regex error.

Is anyone familiar with regex to know what the error at the bracket is?

*perl RAM::RamDisc0.$.checkbashisms/pl --help
Sequence (?<f...) not recognized in regex; 
marked by <-- HERE in
 m/(?:^|\s)(?<f <-- HERE unc>function\s)?\s*(?:[^<>\(\)\[\]\{\};|\s]*[^<>\(\)\[\]\{\};|\s\w][^<>\(\)\[\]\{\};|\s]*)(?(<func>)(?=)|(?<!=))\s*(?(<func>)(?:\(\s*\))?|\(\s*\))\s*([\{|\(]|\Z)/ 
at RAM::RamDisc0.$.checkbashisms/pl line 694.
*

It does look possible to build a newer version of Perl but it requires patience.
If the compatibility questions it asks are answered properly I think it would build.
Thanks.

It’s a named capture.
It’s a ‘modern’ feature of perl, introduced in perl 5.10 (Dec 2007).

It’s a named capture.
It’s a ‘modern’ feature of perl, introduced in perl 5.10 (Dec 2007).

Thank you, that gives me some direction.
I have another ShellCheck that is in Haskell, I was thinking of asking Julie to try building it on her Haskell compiler.
Learning about docker is still another thing for me to do, and it is ‘not the ghc haskell’ which could be a problem.

Perl on RISC OS is a bit of a mess, I believe the build system needs the ancient 5.001, and there is also ports of 5.8.8-1 and 5.14.2 both of which have proved to be pretty flaky with code from other platforms. There needs to be a definitive RISC OS version, and the build system should update to it.