how to retrieve workspace root from .vimrc

[rameshsanth]

This is a basic VIM question.. I'm stumped and cannot figure this out..

I would like to retrieve the Git workspace root and setup the "path" variable appropriately from .vimrc
i tried this.. but keep getting errors

let s = call('FugitiveWorkTree', [])
set path+= s . '/src', s . '/test'

But i get this error.
line 989:
E117: Unknown function: FugitiveWorkTree

Its clear i'm unable to access the Fugitve functions from .vimrc..
I even looked into plugins like lightline how they manage to call Fugitive functions.. just cant figure it out..

Lightline does something like this..
for f in values(s:lightline.component_function)
silent! call call(f, [])
endfor

[tpope]

The reason you can't call FugitiveWorkTree() is because Vim loads your vimrc before it loads plugins. Rather than attempt to work around this, I am instead inclined to direct you to projectionist.vim, which provides a robust implementation of the exact behavior you're looking for. Here's an example config that does what you want:

let g:projectionist_heuristics = {
      \ '.git/': {'path': ['src', 'test']}
      \ }

Even better, change .git/ to something more specific, like pom.xml.