Upstream hashes both the absolute file name and the content of a file
to derive the name for the natively compiled files.  This breaks the
staged install used in guix, as any $GUIX_PROFILE is distinct from
the build directory.  It also breaks grafts, as hardcoded store file
names get rewritten; thus changing the file hash.

Index: emacs-29.1/src/comp.c
===================================================================
--- emacs-29.1.orig/src/comp.c
+++ emacs-29.1/src/comp.c
@@ -4396,26 +4396,18 @@ DEFUN ("comp-el-to-eln-rel-filename", Fc
        Scomp_el_to_eln_rel_filename, 1, 1, 0,
        doc: /* Return the relative name of the .eln file for FILENAME.
 FILENAME must exist, and if it's a symlink, the target must exist.
-If FILENAME is compressed, it must have the \".gz\" extension,
-and Emacs must have been compiled with zlib; the file will be
-uncompressed on the fly to hash its contents.
-Value includes the original base name, followed by 2 hash values,
-one for the file name and another for its contents, followed by .eln.  */)
+FILENAME is resolved relative to `load-path' and only the suffix of
+the first matching path is kept.  If FILENAME is not found to be relative
+to any directory `load-path', it is used as-is to construct the return
+value.  Further, if the NATIVE_COMP_BOGUS_DIRS environment variable is set,
+the first matching prefix mentioned in it will be stripped as well. */)
   (Lisp_Object filename)
 {
   CHECK_STRING (filename);
 
-  /* Resolve possible symlinks in FILENAME, so that path_hash below
-     always compares equal. (Bug#44701).  */
-  filename = Fexpand_file_name (filename, Qnil);
-  char *file_normalized = realpath (SSDATA (ENCODE_FILE (filename)), NULL);
-  if (file_normalized)
-    {
-      filename = DECODE_FILE (make_unibyte_string (file_normalized,
-						   strlen (file_normalized)));
-      xfree (file_normalized);
-    }
+  Lisp_Object rel_name = filename;
 
+  filename = Fexpand_file_name (filename, Qnil);
   if (NILP (Ffile_exists_p (filename)))
     xsignal1 (Qfile_missing, filename);
 
@@ -4423,64 +4415,53 @@ one for the file name and another for it
   filename = Fw32_long_file_name (filename);
 #endif
 
-  Lisp_Object content_hash = comp_hash_source_file (filename);
-
-  if (suffix_p (filename, ".gz"))
-    filename = Fsubstring (filename, Qnil, make_fixnum (-3));
-
-  /* We create eln filenames with an hash in order to look-up these
-     starting from the source filename, IOW have a relation
-
-     /absolute/path/filename.el + content ->
-     eln-cache/filename-path_hash-content_hash.eln.
+  Lisp_Object tail = Vload_path;
+  Lisp_Object name_len = Flength (filename);
 
-     'dlopen' can return the same handle if two shared with the same
-     filename are loaded in two different times (even if the first was
-     deleted!).  To prevent this scenario the source file content is
-     included in the hashing algorithm.
-
-     As at any point in time no more then one file can exist with the
-     same filename, should be possible to clean up all
-     filename-path_hash-* except the most recent one (or the new one
-     being recompiled).
-
-     As installing .eln files compiled during the build changes their
-     absolute path we need an hashing mechanism that is not sensitive
-     to that.  For this we replace if match PATH_DUMPLOADSEARCH or
-     *PATH_REL_LOADSEARCH with '//' before computing the hash.  */
-
-  if (NILP (loadsearch_re_list))
+  FOR_EACH_TAIL_SAFE (tail)
     {
-      Lisp_Object sys_re =
-	concat2 (build_string ("\\`[[:ascii:]]+"),
-		 Fregexp_quote (build_string ("/" PATH_REL_LOADSEARCH "/")));
-      Lisp_Object dump_load_search =
-	Fexpand_file_name (build_string (PATH_DUMPLOADSEARCH "/"), Qnil);
-#ifdef WINDOWSNT
-      dump_load_search = Fw32_long_file_name (dump_load_search);
-#endif
-      loadsearch_re_list = list2 (sys_re, Fregexp_quote (dump_load_search));
-    }
-
-  Lisp_Object lds_re_tail = loadsearch_re_list;
-  FOR_EACH_TAIL (lds_re_tail)
-    {
-      Lisp_Object match_idx =
-	Fstring_match (XCAR (lds_re_tail), filename, Qnil, Qnil);
-      if (BASE_EQ (match_idx, make_fixnum (0)))
+      Lisp_Object len = Flength (XCAR (tail));
+      if (XFIXNUM (name_len) < XFIXNUM (len))
+	continue;
+      else if (EQ (Qt, Fcompare_strings (filename, make_fixnum (0), len,
+					 XCAR (tail), make_fixnum (0), len,
+					 Qnil)))
 	{
-	  filename =
-	    Freplace_match (build_string ("//"), Qt, Qt, filename, Qnil);
+	  filename = Fsubstring (filename, Fadd1 (len), Qnil);
 	  break;
 	}
     }
-  Lisp_Object separator = build_string ("-");
-  Lisp_Object path_hash = comp_hash_string (filename);
-  filename = concat2 (Ffile_name_nondirectory (Fsubstring (filename, Qnil,
-							   make_fixnum (-3))),
-		      separator);
-  Lisp_Object hash = concat3 (path_hash, separator, content_hash);
-  return concat3 (filename, hash, build_string (NATIVE_ELISP_SUFFIX));
+
+  if (Ffile_name_absolute_p (filename))
+    filename = rel_name;
+
+  Lisp_Object bogus_dirs =
+    Fgetenv_internal (build_string ("NATIVE_COMP_BOGUS_DIRS"), Qnil);
+
+  if (!NILP (bogus_dirs))
+  {
+    tail = CALL2I (split-string, bogus_dirs, build_string (":"));
+
+    FOR_EACH_TAIL_SAFE (tail)
+      {
+	Lisp_Object len = Flength (XCAR (tail));
+	if (XFIXNUM (name_len) < XFIXNUM (len))
+	  continue;
+	else if (EQ (Qt, Fcompare_strings (filename, make_fixnum (0), len,
+					   XCAR (tail), make_fixnum (0), len,
+					   Qnil)))
+	  {
+	    filename = Fsubstring (filename, Fadd1 (len), Qnil);
+	    break;
+	  }
+      }
+  }
+
+  if (suffix_p (filename, ".gz"))
+    filename = Fsubstring (filename, Qnil, make_fixnum (-3));
+
+  return concat2(Fsubstring (filename, Qnil, make_fixnum (-3)),
+		 build_string (NATIVE_ELISP_SUFFIX));
 }
 
 DEFUN ("comp-el-to-eln-filename", Fcomp_el_to_eln_filename,
@@ -4494,13 +4475,7 @@ If BASE-DIR is non-nil, use it as the di
 non-absolute BASE-DIR is interpreted as relative to `invocation-directory'.
 If BASE-DIR is omitted or nil, look for the first writable directory
 in `native-comp-eln-load-path', and use as BASE-DIR its subdirectory
-whose name is given by `comp-native-version-dir'.
-If FILENAME specifies a preloaded file, the directory for the .eln
-file is the \"preloaded/\" subdirectory of the directory determined
-as described above.  FILENAME is considered to be a preloaded file if
-the value of `comp-file-preloaded-p' is non-nil, or if FILENAME
-appears in the value of the environment variable LISP_PRELOADED;
-the latter is supposed to be used by the Emacs build procedure.  */)
+whose name is given by `comp-native-version-dir'. */)
   (Lisp_Object filename, Lisp_Object base_dir)
 {
   Lisp_Object source_filename = filename;
@@ -4541,19 +4516,7 @@ the latter is supposed to be used by the
 
   if (!file_name_absolute_p (SSDATA (base_dir)))
     base_dir = Fexpand_file_name (base_dir, Vinvocation_directory);
-
-  /* In case the file being compiled is found in 'LISP_PRELOADED' or
-     `comp-file-preloaded-p' is non-nil target for output the
-     'preloaded' subfolder.  */
-  Lisp_Object lisp_preloaded =
-    Fgetenv_internal (build_string ("LISP_PRELOADED"), Qnil);
   base_dir = Fexpand_file_name (Vcomp_native_version_dir, base_dir);
-  if (comp_file_preloaded_p
-      || (!NILP (lisp_preloaded)
-	  && !NILP (Fmember (CALL1I (file-name-base, source_filename),
-			     Fmapcar (intern_c_string ("file-name-base"),
-				      CALL1I (split-string, lisp_preloaded))))))
-    base_dir = Fexpand_file_name (build_string ("preloaded"), base_dir);
 
   return Fexpand_file_name (filename, base_dir);
 }
Index: emacs-29.1/src/Makefile.in
===================================================================
--- emacs-29.1.orig/src/Makefile.in
+++ emacs-29.1/src/Makefile.in
@@ -553,6 +553,7 @@ shortlisp := $(filter-out ${shortlisp_fi
 ## We don't really need to sort, but may as well use it to remove duplicates.
 shortlisp := loaddefs.el loadup.el $(sort ${shortlisp})
 export LISP_PRELOADED = ${shortlisp}
+export NATIVE_COMP_BOGUS_DIRS
 lisp = $(addprefix ${lispsource}/,${shortlisp})
 
 ## Construct full set of libraries to be linked.