That autocmd as written shouldn't work at all. There must not be any whitespace inside the
au BufNewFile,BufRead *.sv,*.v so ~/.vim/syntax/verilogsystemverilog.vim
Additionally, you're circumventing Vim's filetype mechanism completely. Even if you don't use filetype plugins (which can supply specific indent, formatting, etc. settings and mappings), it's advisable to follow that mechanism.
To enable this, put
filetype on in your
~/.vimrc. Then (following
:help new-filetype), create a custom detection
~/.vim/ftdetect/verilogsystemverilog.vim with the following contents:
au BufRead,BufNewFile *.sv,*.v setfiletype verilogsystemverilog
This will automatically set
'syntax', and with that, loads your syntax script (from
~/.vim/syntax/verilogsystemverilog.vim, but without having you specify the full path directly).
PS: You have
set exrc twice, and you could even combine all into a single command
set exrc ruler.