I'm try to write a test for following src block:

#+begin_src sh :results link :file "test.txt"
echo "hello" > test.txt
echo "test"
#+end_src

#+RESULTS[<2018-04-08 18:30:51> 22a787defa349526768722f4bfc8509dd16ab154]:
[[file:test.txt]]

And here is my ert test:

(ert-deftest test-ob/result-file-link-type-header-argument ()
  "Ensure that the result is a link to a file.
The file is just a link to :file value. Inhibit non-empty result write to :file."
  (org-test-with-temp-text
   "
#+begin_src sh :results link :file \"/tmp/test.txt\"
echo \"hello\" > /tmp/test.txt
echo \"test\"
#+end_src"
   (org-babel-next-src-block 1)
   (org-babel-execute-src-block)
   (goto-char (point-min))
   (should (search-forward "[[file:test.txt]]" nil nil))
   (should (with-temp-buffer
   	     (insert-file-contents "/tmp/test.txt")
   	     (string=
   	      "hello\n"
   	      (buffer-substring-no-properties (point-min) (point-max)))))
   ))

I run test with async shell command in Emacs:

make BTEST_RE="test-ob/result-file-link-type-header-argument" test-dirty
   
But I got error:

```
selected tests: test-ob/result-file-link-type-header-argument
Running 1 tests (2018-04-08 20:52:41+0800, selector ‘"test-ob/result-file-link-type-header-argument"’)
executing Sh code block...
Code block evaluation complete.
Test test-ob/result-file-link-type-header-argument backtrace:
  search-forward("[[file:test.txt]]" nil nil nil)
  apply(search-forward ("[[file:test.txt]]" nil nil))
  (setq value-1950 (apply fn-1948 args-1949))
  (unwind-protect (setq value-1950 (apply fn-1948 args-1949)) (setq fo
  (if (unwind-protect (setq value-1950 (apply fn-1948 args-1949)) (set
  (let (form-description-1952) (if (unwind-protect (setq value-1950 (a
  (let ((value-1950 'ert-form-evaluation-aborted-1951)) (let (form-des
  (let* ((fn-1948 (function search-forward)) (args-1949 (condition-cas
  (progn (org-mode) (let ((point (string-match "<point>" inside-text))
  (unwind-protect (progn (org-mode) (let ((point (string-match "<point
  (save-current-buffer (set-buffer temp-buffer) (unwind-protect (progn
  (let ((temp-buffer (generate-new-buffer " *temp*"))) (save-current-b
  (let ((inside-text (if (stringp "\n#+begin_src sh :results link :fil
  (lambda nil (let ((inside-text (if (stringp "\n#+begin_src sh :resul
  ert--run-test-internal(#s(ert--test-execution-info :test #s(ert-test
  ert-run-test(#s(ert-test :name test-ob/result-file-link-type-header-
  ert-run-or-rerun-test(#s(ert--stats :selector "test-ob/result-file-l
  ert-run-tests("test-ob/result-file-link-type-header-argument" #f(com
  ert-run-tests-batch("test-ob/result-file-link-type-header-argument")
  ert-run-tests-batch-and-exit("test-ob/result-file-link-type-header-a
  (let ((org-id-track-globally t) (org-test-selector (if org-test-sele
  org-test-run-batch-tests("test-ob/result-file-link-type-header-argum
  eval((org-test-run-batch-tests org-test-select-re))
  command-line-1(("--eval" "(setq vc-handled-backends nil org-startup-
  command-line()
  normal-top-level()
Test test-ob/result-file-link-type-header-argument condition:
    (search-failed "[[file:test.txt]]")
   FAILED  1/1  test-ob/result-file-link-type-header-argument (0.032747 sec)

Ran 1 tests, 0 results as expected, 1 unexpected (2018-04-08 20:52:42+0800, 0.877523 sec)

1 unexpected results:
   FAILED  test-ob/result-file-link-type-header-argument

make: *** [mk/targets.mk:105: test-dirty] Error 1
```

I tried many modification, I write this test based on existing test:

(ert-deftest test-ob/file-desc-header-argument ()
  "Test that the :file-desc header argument is used."
  (org-test-with-temp-text "#+begin_src emacs-lisp :results file :file-desc bar
  \"foo\"
#+end_src

#+begin_src emacs-lisp :results file :file-desc
  \"foo\"
#+end_src"
    (org-babel-execute-src-block)
    (org-babel-next-src-block 1)
    (org-babel-execute-src-block)
    (goto-char (point-min))
    (should (search-forward "[[file:foo][bar]]" nil t))
    (should (search-forward "[[file:foo][foo]]" nil t))))

Don't know why my test error. Can't find out what's wrong from truncated make test output.

I included my patch in attachment.