Debugger entered--Lisp error: (wrong-type-argument integerp nil)
  fldd--get-dub-package-dirs-output("Error executing command describe: Root package SUB_PACKAGE_1 contains reference to invalid package PACKAGE:SUB_PACKAGE_2\n\n")
  fldd--get-dub-package-dirs()
  ac-dcd-find-imports-dub()
  ac-dcd-add-imports()
  call-interactively(ac-dcd-add-imports record nil)
  command-execute(ac-dcd-add-imports record)
  execute-extended-command(nil "ac-dcd-add-imports")
  call-interactively(execute-extended-command nil nil)

Debugger entered--Lisp error: (json-string-format "doesn't start with '\"'!")
  signal(json-string-format ("doesn't start with '\"'!"))
  (if (char-equal (json-peek) 34) nil (signal (quote json-string-format) (list "doesn't start with '\"'!")))
  json-read-string()
  json-read-object()
  apply(json-read-object nil)
  json-read()
  json-read-object()
  apply(json-read-object nil)
  json-read()
  json-read-file("~/justd/dub.json")
  eval((json-read-file "~/justd/dub.json"))
  eval-expression((json-read-file "~/justd/dub.json") nil)
  funcall-interactively(eval-expression (json-read-file "~/justd/dub.json") nil)
  call-interactively(eval-expression nil nil)
  command-execute(eval-expression)

Debugger entered--Lisp error: (json-readtable-error 114)
  signal(json-readtable-error (114))
  json-read()
  json-read-from-string("rawRead must take a non-empty buffer\n")
  fldd--set-variables-from-json-string("rawRead must take a non-empty buffer\n")
  fldd--set-variables-from-dub-describe("/home/per/")
  flycheck-dmd-dub-set-variables()
  run-hooks(change-major-mode-after-body-hook prog-mode-hook c-mode-common-hook d-mode-hook d-mode-hook)
  apply(run-hooks (change-major-mode-after-body-hook prog-mode-hook c-mode-common-hook d-mode-hook d-mode-hook))
  run-mode-hooks(d-mode-hook)
  d-mode()
  funcall-interactively(d-mode)
  call-interactively(d-mode record nil)
  command-execute(d-mode record)
  #f(compiled-function (cmd) #<bytecode 0x192843d>)("d-mode")
  ivy-call()
  ...