Why are my dir-locals always malformed

Question

I was reading about dir-locals and wanted to set up per project settings. However whatever I try results in a malformed function. Why is this ?

.dir-locals.el:4:1:Warning: ‘(php-mode (php-executable . /usr/bin/php))’ is a
malformed function

So I tried this as the most basic example I could think of, and even this raises an error.

((php-mode
  (php-executable . /usr/bin/php)))

So what am i doing wrong? I edit the file and then compile it to check things are working and checked multiple examples online and they all seem to use this format.

From the answers below this is an example I wanted to make work, the above was just a simpler test.

((nil . ((pony-settings (make-pony-project :python "/docker:root@app_django_1:/usr/local/bin/python" :pythonpath "/app" :settings "local_settings_file" :appsdir "/app") ))))

This is where my issues stemmed from, I can switch to a file and I hit an error which is what made me try and compile the code so I could test quickly.

eval: Invalid function: (make-pony-project :python "/docker:root@app_django_1:/usr/local/bin/python" :pythonpath "/app" :settings "local_settings_file" :appsdir "/app")

Perhaps this should be another question now, but in away this is still an issue I am getting an error but cant modify and apply changes quickly to see if its valid. Anyone have any idea on the above error ?

Answer 1

For the original question (repeating my comment):

As others have pointed out, that value needs to be a string: "/usr/bin/php". You need to manually type the quotes because add-dir-local-variable has no idea what type of value is required/valid for any given variable, so string values need to be made explicit. (Despite looking like a file path, the value you'd actually entered was a symbol rather than a string.)

---

For the revised/new question:

((nil . ((pony-settings (make-pony-project ...

is the same as:

((nil . ((pony-settings . ((make-pony-project ...

So you're setting pony-settings to ((make-pony-project ...))

And it sounds like that form is then evaluated like so:

((make-pony-project ...))

Hence:

eval: Invalid function: (make-pony-project ...)

Because while make-pony-project may be the name of a function, the form (make-pony-project ...) is not the name of a function.

So in summary, I suspect you're missing a dot. Try:

((nil . ((pony-settings . (make-pony-project ...

See also the "Notation" heading at https://www.emacswiki.org/emacs/DirectoryVariables#toc1