Update

emacs.el

@@ -2021,18 +2021,22 @@ This variable is intended to be explicitly set by user.
 When nil, `with-venv' tries to find suitable venv dir.")
 
 (defmacro with-venv-dir (dir &rest body)
-  "Set python environment to DIR and execute BODY."
+  "Set python environment to DIR and execute BODY.
+
+This macro does not check if DIR is a valid python environemnt.
+If dir is nil, execute BODY as usual."
   `(let ((--with-venv-process-environment-orig (cl-copy-list process-environment))
          (--with-venv-exec-path-orig (cl-copy-list exec-path)))
      (unwind-protect
          (progn
-           ;; Do the same thing that bin/activate does
-           (setq exec-path
-                 (cons (concat ,dir "/bin")
-                       exec-path))
-           (setenv "VIRTUAL_ENV" ,dir)
-           (setenv "PATH" (concat ,dir "/bin:" (or (getenv "PATH") "")))
-           (setenv "PYTHONHOME")
+           (when dir
+             ;; Do the same thing that bin/activate does
+             (setq exec-path
+                   (cons (concat ,dir "/bin")
+                         exec-path))
+             (setenv "VIRTUAL_ENV" ,dir)
+             (setenv "PATH" (concat ,dir "/bin:" (or (getenv "PATH") "")))
+             (setenv "PYTHONHOME"))
            ,@body)
        (setq process-environment
              --with-venv-process-environment-orig)
@@ -2042,25 +2046,37 @@ When nil, `with-venv' tries to find suitable venv dir.")
 (defmacro with-venv (&rest body)
   "Execute BODY with venv enabled.
 
-This function tries to find suitable venv dir, or raise error when none found."
+This function tries to find suitable venv dir, or run BODY as usual when no
+suitable environment was found."
   `(with-venv-dir
     ;; If set explicitly use it
     ,(or with-venv-venv-dir
          (with-venv-find-venv-dir))
     ,@body))
 
+(defvar-local with-venv-previously-used nil
+  "Previously used venv dir path.")
 (defun with-venv-find-venv-dir (&optional dir)
-  "Try to find venv dir for DIR or raise error when none found."
+  "Try to find venv dir for DIR.
+If none found return nil."
   (with-temp-buffer
     (when dir
       (cd dir))
-    (or
-     ;; Check pipenv
-     (with-venv--find-venv-dir-pipenv)
-     ;; Check poetry
-     (with-venv--find-venv-dir-poetry)
-     ;; Search for .venv dir
-     (with-venv--find-venv-dir-by-name))))
+    (let ((result (or
+                   ;; Check used previously
+                   (with-venv-check-exists
+                    with-venv-previously-used)
+                   ;; Check pipenv
+                   (with-venv-check-exists
+                    (with-venv--find-venv-dir-pipenv))
+                   ;; Check poetry
+                   (with-venv-check-exists
+                    (with-venv--find-venv-dir-poetry))
+                   ;; Search for .venv dir
+                   (with-venv-check-exists
+                    (with-venv--find-venv-dir-by-name)))))
+      (setq with-venv-previously-used
+            result))))
 
 (defun with-venv--find-venv-dir-pipenv ()
   "Try to find venv dir via pipenv."
@@ -2087,9 +2103,17 @@ This function tries to find suitable venv dir, or raise error when none found."
   (let ((dir (locate-dominating-file default-directory
                                      ".venv")))
     (when dir
+      ;; TODO: check with -check-exists
       (expand-file-name ".venv"
                         dir))))
 
+(defun with-venv-check-exists (dir)
+  "Return DIR as is if \"bin\" directory was found under DIR."
+  (and dir
+       (file-directory-p (expand-file-name "bin"
+                                           dir))
+       dir))
+
 
 ;; (with-venv (:dir default-directory) (message "a"))
 ;; (with-venv () (message "a"))