Re: let*: Wrong type argument: stringp, nil

[Emanuel Berg via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>]

Hongyi Zhao wrote:

> (defun try/pyvenv-workon ()
>   (when (locate-dominating-file (buffer-file-name) ".python-version")
>       ;https://emacs.stackexchange.com/questions/9474/let-statement-throws-error-on-assigning-a-form-to-a-variable
>       (let ((file (concat (locate-dominating-file (buffer-file-name)
> ".python-version") ".python-version")))
>            (pyvenv-workon (with-temp-buffer
>                            (insert-file-contents file)
>                              (nth 0 (split-string (buffer-string))))))))
>
> BTW, should I use `let' or `let*' here?

`let*' always works, `let' works when there is no references
to previous bindings in any binding...

So if it works and you have let, you have done the
right thing!

In theory, because of the independence of the individual
bindings with let, it can be used to compute in parallel - but
I don't think that actually happens - an urban legend ...

In your code you only have "file" so while both would work,
let* is unnecessary ...

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