I can reproduce by running :GBrowse on e.g. plugin/fugitive.vim on:

• MacVim r182 (Vim 9.1.1887)

But not on:

• nvim v0.11.2
• vim 9.1 (bundled with macos 26.1)

I have rhubarb.vim installed alongside, and then when running :GBrowse with it disabled we do not get the error but:

fugitive: no GBrowse handler installed for 'https://github.com/tpope/vim-fugitive'