Specify particular Rakudo version in Raku module

Question

Today, I learned in IRC chat that

my @a = [9, 4, 3, 2, 7];
say @a.sort(:k) # (3 2 1 4 0)

is available since Rakudo 2023.08. I want my module to use this feature. Is there inbuilt mechanism to specify this in module, may be by modifying META6.json ?

Like if the Rakudo is earlier than 2023.08, fail the installation of module.

What I know is we can specify 6.c, 6.d, 6.e e.g:

"raku": "6.d"

in META6.json file. This however does not address the issue.

Answer 1

Sadly current Raku does not have an inbuilt mechanism to control the VM version such as 2023.08 (eg. via META6.json) below the level of major raku release such as 6.d.

I suggest (and would support) this as a new feature request. In the meantime, here is a rough and ready workaround:

die "must be raku v2023.08 or greater" 
unless $*VM.version ~~ v2023.08+;

^^ put this in your test if you want installation to fail

• https://docs.raku.org/type/Version
• https://docs.raku.org/language/variables#$*VM