Why 'file' local variable is obsolete?

Why 'file' local variable is obsolete?

[Przemysław Wojnowski]

Hello everybody,

Having the following code with 'file' as local var:
(defun file-processor (filename)
   (let ((file (expand-file-name filename)))
     (message "Processing a file...")))

Compiling the file gives warning:
In file-processor:
aoeu.el:2:10:Warning: `file' is an obsolete variable (as of 25.1); use 'file
     instead

I do not read every single email on the list, so maybe I missed something, but 
why there are byte compilation warnings for some variable names?
For example it is for 'file', 'tree', 'status', which are quite common local 
names. Moreover the message is not too helpful.

Thanks,
Przemysław

Re: Why 'file' local variable is obsolete?

[Stefan Monnier]

> (defun file-processor (filename)
>   (let ((file (expand-file-name filename)))
>     (message "Processing a file...")))

> Compiling the file gives warning:
> In file-processor:
> aoeu.el:2:10:Warning: `file' is an obsolete variable (as of 25.1); use 'file
>     instead

I put the above three lines of code into ~/tmp/foo.el, then did

   emacs -Q ~/tmp/foo.el
   M-x byte-compile RET RET

but did not see this warning about `file' being obsolete.

Please make it a bug report where you provide all details necessary to
try and reproduce your problem.


        Stefan