Fix #3812: direnv not in scope for babel execution

modules/tools/direnv/config.el

@@ -40,4 +40,26 @@
     "Don't try to use direnv if the executable isn't present."
     :before-while #'envrc-mode
     (or (executable-find "direnv")
-        (ignore (doom-log "Couldn't find direnv executable")))))
+        (ignore (doom-log "Couldn't find direnv executable"))))
+
+  ;; HACK envrc-mode only affects the current buffer's environment, which is
+  ;;      generally what we want, except when we're running babel blocks in
+  ;;      org-mode, because there may be state or envvars those blocks need to
+  ;;      read. In order to perpetuate the org buffer's environment into the
+  ;;      execution of the babel block we need to temporarily change the global
+  ;;      environment. Let's hope it runs quickly enough that its effects aren't
+  ;;      felt in other buffers in the meantime!
+  (defvar +direnv--old-environment nil)
+  (defadvice! +direnv-persist-environment-a (orig-fn &rest args)
+    :around #'org-babel-execute-src-block
+    (if +direnv--old-environment
+        (apply orig-fn args)
+      (setq-default +direnv--old-environment
+                    (cons (default-value 'process-environment)
+                          (default-value 'exec-path))
+                    exec-path exec-path
+                    process-environment process-environment)
+      (unwind-protect (apply orig-fn args)
+        (setq-default process-environment (car +direnv--old-environment)
+                      exec-path (cdr +direnv--old-environment)
+                      +direnv--old-environment nil)))))