vim-ledger spews errors

[l29ah]

vim 9.0 here. Todays master tells me this when i open a ledger file:

Error detected while processing /etc/vim/vimrc[92]../usr/share/vim/vim90/syntax/syntax.vim[43]..BufRead Autocommands for "*.ldg"..FileType Autocommands for "*"..Syntax Autocommands for "*"..function <SNR>3_SynSet[25]..script /usr/share/vim/vimfiles/syntax/ledger.vim:
line   15:
E121: Undefined variable: g:ledger_is_hledger
line   22:
E121: Undefined variable: b:is_hledger
line   70:
E121: Undefined variable: s:line_comment_chars
line   74:
E121: Undefined variable: b:is_hledger
line   88:
E121: Undefined variable: b:is_hledger
line  147:
E121: Undefined variable: b:is_hledger