Fixed that bug

lisp/llvm-lib/llvm-act-on-file/act-on-c-file.el

@@ -127,7 +127,6 @@
              (make-variable-buffer-local 'compilation-error-regexp-alist)
              (setq compilation-error-regexp-alist nil))
 
-           ;; TODO: This doesn't ACTUALLY survive a call to #'recompile
            (make-variable-buffer-local 'compilation-finish-functions)
            (add-to-list 'compilation-finish-functions
                         #'ll/c-file-sentinel)))))

lisp/llvm-lib/my-comp-minor-mode.el

@@ -37,10 +37,16 @@ commands of Compilation major mode are available.  See
     (compilation--unsetup)))
 
 (defun my/enable-comp-keys-if-separate-mode (orig &rest args)
-  (aprog1 (apply orig args)
-    (when (cadr args)
-      (with-current-buffer it
-        (compilation-minor-mode)))))
+  (let ((hook compilation-finish-functions))
+    (aprog1 (apply orig args)
+      (when (cadr args)
+        (with-current-buffer it
+          (compilation-minor-mode))
+
+        (setq-local compilation-finish-functions
+                    (seq-uniq
+                     (append compilation-finish-functions
+                             hook)))))))
 
 (advice-add #'compilation-start
             :around