error when started in a directory without .gitignore

[tpapp]

Backtrace:

Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  expand-file-name(nil)
  (or (expand-file-name (locate-dominating-file default-directory ".gitignore")) default-directory)
  lsp-julia--get-root()
  lsp--start()
  lsp-mode()
  run-hooks(ess-julia-mode-hook)
  ess-julia-mode()
  set-auto-mode-0(ess-julia-mode nil)
  set-auto-mode()
  normal-mode(t)
  after-find-file(nil t)
  find-file-noselect-1(#<buffer foo.jl> "/tmp/foo.jl" nil nil "/tmp/foo.jl" (40111715 64769))
  find-file-noselect("/tmp/foo.jl" nil nil nil)
  find-file("/tmp/foo.jl")
  helm-find-file-or-marked("/tmp/foo.jl")
  helm-execute-selection-action-1()
  helm-execute-selection-action()
  helm-internal(helm-source-find-files "/home/tamas/" "Find files or url: " nil nil "*helm find files*" nil nil nil)
  apply(helm-internal (helm-source-find-files "/home/tamas/" "Find files or url: " nil nil "*helm find files*" nil nil nil))
  helm(helm-source-find-files "/home/tamas/" "Find files or url: " nil nil "*helm find files*" nil nil nil)
  apply(helm (helm-source-find-files "/home/tamas/" "Find files or url: " nil nil "*helm find files*" nil nil nil))
  helm(:sources helm-source-find-files :input "/home/tamas/" :case-fold-search smart :preselect nil :ff-transformer-show-only-basename t :default nil :prompt "Find files or url: " :buffer "*helm find files*")
  helm-find-files-1("/home/tamas/" nil)
  helm-find-files(nil)
  funcall-interactively(helm-find-files nil)
  call-interactively(helm-find-files nil nil)
  command-execute(helm-find-files)