Incompatible with (setq vc-display-status nil)

[jaredr]

Was receiving errors like the following:
Error during redisplay: (eval (doom-modeline-segment--vcs)) signaled (args-out-of-range " Git" 5 nil)

It appears that I'd customized the vc-display-status variable to nil, and this causes vc-mode to not include branch information. doom-modeline-update-vcs-text tries to substring the branch name out of vc-mode and ends up out of range.

The existing check against vc-mode (and buffer-file-name) is inadequate because vc-mode isn't nil, it's something like " Git".

Steps to reproduce the behavior:
On emacs 26.3:
eval (setq vc-display-status nil), then save or visit a file under git version control.