Weird issues with built-in functions not being found/not working

[Fuco1]

I'm having really odd issues with some built-in functions, such as newline complaining about invalid number of arguments and such.

Traceback (most recent call last):

  (progn (let ((wconfig (current-window-configuration))) (unwind-protect (pr...

  (let ((wconfig (current-window-configuration))) (unwind-protect (progn (le...

  (unwind-protect (progn (let ((case-fold-search nil)) (let ((temp-buffer (g...

  (progn (let ((case-fold-search nil)) (let ((temp-buffer (generate-new-buff...

  (let ((case-fold-search nil)) (let ((temp-buffer (generate-new-buffer " *t...

  (let ((temp-buffer (generate-new-buffer " *temp*"))) (save-current-buffer ...

  (save-current-buffer (set-buffer temp-buffer) (unwind-protect (progn (set-...

  (unwind-protect (progn (set-window-buffer (selected-window) (current-buffe...

  (progn (set-window-buffer (selected-window) (current-buffer)) (set-input-m...

  (my-newline)

  (newline nil :interactive)

error: (wrong-number-of-arguments #[(&optional arg) "\306 \210n\205

\304`\305	!Z`\"\210\212

b\210\306 \210\307\310!\203&\311 \312V\203&`\313 |\210)\206/\314\315\316\"\207" [use-hard-newlines arg beforepos was-page-start set-hard-newline-properties prefix-numeric-value beginning-of-line looking-at "[ 	]$" current-left-margin 0 line-end-position move-to-left-margin nil t] 4] ((byte-code "\301\30\"\207" [postproc remove-hook post-self-insert-hook] 3)) add-hook post-self-insert-hook self-insert-command prefix-numeric-value nil postproc] 3 1906062 "*P"] 2)

Or that the function window-text-width does not exist

Traceback (most recent call last):

  (progn (let ((file (make-temp-file "tests"))) (unwind-protect (let ((wconf...

  (let ((file (make-temp-file "tests"))) (unwind-protect (let ((wconfig (cur...

  (unwind-protect (let ((wconfig (current-window-configuration))) (unwind-pr...

  (let ((wconfig (current-window-configuration))) (unwind-protect (progn (le...

  (unwind-protect (progn (let ((case-fold-search nil)) (let ((temp-buffer (g...

  (progn (let ((case-fold-search nil)) (let ((temp-buffer (generate-new-buff...

  (let ((case-fold-search nil)) (let ((temp-buffer (generate-new-buffer " *t...

  (let ((temp-buffer (generate-new-buffer " *temp*"))) (save-current-buffer ...

  (save-current-buffer (set-buffer temp-buffer) (unwind-protect (progn (set-...

  (unwind-protect (progn (set-window-buffer (selected-window) (current-buffe...

  (progn (set-window-buffer (selected-window) (current-buffer)) (set-input-m...

  (let ((shut-up-sink (generate-new-buffer " *shutup*")) (inhibit-message t)...

  (let (--cl-shut-up-current-output--) (setq --cl-shut-up-current-output-- (...

  (if shut-up-ignore (progn (write-region nil nil file) (set-visited-file-na...

  (unwind-protect (let* ((vnew (function (lambda (char) (shut-up-insert-to-b...

  (let* ((vnew (function (lambda (char) (shut-up-insert-to-buffer char shut-...

  (unwind-protect (progn (fset (quote load) (function shut-up-load)) (fset (...

  (progn (fset (quote load) (function shut-up-load)) (fset (quote write-regi...

  (let ((org-agenda-files (list (buffer-file-name))) (org-agenda-span (quote...

  (org-agenda-list nil 736484)

  (byte-code \2061	\203

#\202-\...

  (org-agenda-finalize)

  (org-agenda-align-tags)

  (window-text-width)

error: (void-function window-text-width)

All the tests pass fine locally. I'm not quite sure what is going on. I'm using cask and buttercup to run the tests, you can see the job here: https://travis-ci.org/Fuco1/.emacs.d/jobs/288232603