diff --git a/compile.c b/compile.c
index a7308c66b1b50e..2ff207928a57e6 100644
--- a/compile.c
+++ b/compile.c
@@ -12680,7 +12680,7 @@ typedef uint32_t ibf_offset_t;
 
 #define IBF_MAJOR_VERSION ISEQ_MAJOR_VERSION
 #ifdef RUBY_DEVEL
-#define IBF_DEVEL_VERSION 7
+#define IBF_DEVEL_VERSION 8
 #define IBF_MINOR_VERSION (ISEQ_MINOR_VERSION * 10000 + IBF_DEVEL_VERSION)
 #else
 #define IBF_MINOR_VERSION ISEQ_MINOR_VERSION
@@ -13774,7 +13774,6 @@ ibf_dump_iseq_each(struct ibf_dump *dump, const rb_iseq_t *iseq)
     const struct rb_iseq_constant_body *body = ISEQ_BODY(iseq);
 
     const VALUE location_pathobj_index = ibf_dump_object(dump, body->location.pathobj); /* TODO: freeze */
-    const VALUE location_base_label_index = ibf_dump_object(dump, body->location.base_label);
     const VALUE location_label_index = ibf_dump_object(dump, body->location.label);
 
 #if IBF_ISEQ_ENABLE_LOCAL_BUFFER
@@ -13856,7 +13855,6 @@ ibf_dump_iseq_each(struct ibf_dump *dump, const rb_iseq_t *iseq)
     ibf_dump_write_small_value(dump, IBF_BODY_OFFSET(param_opt_table_offset));
     ibf_dump_write_small_value(dump, param_keyword_offset);
     ibf_dump_write_small_value(dump, location_pathobj_index);
-    ibf_dump_write_small_value(dump, location_base_label_index);
     ibf_dump_write_small_value(dump, location_label_index);
     ibf_dump_write_small_value(dump, body->location.first_lineno);
     ibf_dump_write_small_value(dump, body->location.node_id);
@@ -13972,7 +13970,6 @@ ibf_load_iseq_each(struct ibf_load *load, rb_iseq_t *iseq, ibf_offset_t offset)
     const ibf_offset_t param_opt_table_offset = (ibf_offset_t)IBF_BODY_OFFSET(ibf_load_small_value(load, &reading_pos));
     const ibf_offset_t param_keyword_offset = (ibf_offset_t)ibf_load_small_value(load, &reading_pos);
     const VALUE location_pathobj_index = ibf_load_small_value(load, &reading_pos);
-    const VALUE location_base_label_index = ibf_load_small_value(load, &reading_pos);
     const VALUE location_label_index = ibf_load_small_value(load, &reading_pos);
     const int location_first_lineno = (int)ibf_load_small_value(load, &reading_pos);
     const int location_node_id = (int)ibf_load_small_value(load, &reading_pos);
@@ -14137,7 +14134,6 @@ ibf_load_iseq_each(struct ibf_load *load, rb_iseq_t *iseq, ibf_offset_t offset)
     load->current_buffer = &load->global_buffer;
 #endif
 
-    RB_OBJ_WRITE(iseq, &load_body->location.base_label,    ibf_load_location_str(load, location_base_label_index));
     RB_OBJ_WRITE(iseq, &load_body->location.label,         ibf_load_location_str(load, location_label_index));
 
 #if IBF_ISEQ_ENABLE_LOCAL_BUFFER
diff --git a/depend b/depend
index 166d1266703288..a18eebe3fa96b1 100644
--- a/depend
+++ b/depend
@@ -36,7 +36,7 @@
 # mkdepend: depends vmtc.inc => {$(VPATH)}vmtc.inc
 # mkdepend: undef parse.y => RIPPER
 
-.deps/depend update-dependencies: $(srcdir)/depend \
+.deps/depend update-dependencies: $(REVISION_H) $(srcdir)/depend \
                                   $(srcdir)/tool/mkdepend.rb \
                                   $(srcdir)/lib/mkmf/depend.rb
 	$(BASERUBY) "$(srcdir)/tool/mkdepend.rb" --root="$(srcdir)" \
diff --git a/doc/file/filesystem_modes.md b/doc/file/filesystem_modes.md
index 33b69c386119e7..078853591998ff 100644
--- a/doc/file/filesystem_modes.md
+++ b/doc/file/filesystem_modes.md
@@ -50,13 +50,17 @@ Dir.rmdir(dirpath)
 You can use one of these methods to change the [permissions][permissions]
 and [special bits][special bits] (but not the [file type][file type]):
 
+- File#chmod.
 - File::chmod.
+- File::lchmod (does not follow symbolic links).
+- FileUtils#chmod.
+- FileUtils#chmod_R.
 - FileUtils::chmod.
 - FileUtils::chmod_R.
-- File#chmod.
 - Pathname#chmod.
-- FileUtils#chmod.
-- FileUtils#chmod_R.
+- Pathname#lchmod (does not follow symbolic links).
+
+The actual effects of these methods is filesystem-dependent.
 
 ## Permissions
 
diff --git a/file.c b/file.c
index 6c46b908440008..995111e89d88a7 100644
--- a/file.c
+++ b/file.c
@@ -2946,26 +2946,28 @@ chmod_internal(const char *path, void *mode)
 
 /*
  *  call-seq:
- *     File.chmod(mode, *paths) -> integer
+ *    File.chmod(mode, *paths) -> integer
  *
- *  Changes the mode (i.e., permissions) of the entries of each the given +paths+;
- *  see {File Permissions}[rdoc-ref:File@File+Permissions].
- *  Returns the count of the given +paths+:
+ *  Changes the modes of each of the entries at each the given +paths+;
+ *  returns the count of the given +paths+.
+ *  See {Filesystem Modes}[rdoc-ref:file/filesystem_modes.md]
+ *  and especially {Setting a Mode}[rdoc-ref:file/filesystem_modes.md@Setting+a+Mode].
  *
- *    filepath = 't.tmp'
- *    File.write(filepath, 'foo')
- *    dirpath = 'tempdir'
- *    Dir.mkdir(dirpath)
- *    File::Stat.new(filepath).mode.to_s(8) # => "100664"
- *    File::Stat.new(dirpath).mode.to_s(8)  # => "40775"
- *    File.chmod(0775, filepath, dirpath)   # => 2
- *    File::Stat.new(filepath).mode.to_s(8) # => "100775"
- *    File::Stat.new(dirpath).mode.to_s(8)  # => "40775"
- *    File.chmod(0664, filepath, dirpath)   # => 2
- *    File::Stat.new(filepath).mode.to_s(8) # => "100664"
- *    File::Stat.new(dirpath).mode.to_s(8)  # => "40664"
- *    File.delete(filepath)
- *    Dir.rmdir(dirpath)
+ *  These examples use
+ *  a {helper method}[rdoc-ref:file/filesystem_modes.md@Helper+Method], +mode+,
+ *  that displays a mode both in octal digits and in characters:
+ *
+ *    dirpath = 'doc/foo'
+ *    filepath = File.join(dirpath, 't.tmp')
+ *    Dir.mkdir(dirpath)          # Create directory.
+ *    mode(dirpath)               # => "040775 drwxrwxr-x"
+ *    File.write(filepath, 'bar') # Create file.
+ *    mode(filepath)              # => "100664 -rw-rw-r--"
+ *    File.chmod(0755, filepath)  # Change file mode.
+ *    mode(filepath)              # => "100755 -rwxr-xr-x"
+ *    File.chmod(0664, dirpath)   # Change directory mode.
+ *    mode(dirpath)               # => "040664 drw-rw-r--"
+ *    FileUtils.rm_rf(dirpath)    # Clean up.
  *
  */
 
@@ -3005,15 +3007,25 @@ rb_fchmod(struct rb_io* io, mode_t mode)
 
 /*
  *  call-seq:
- *     file.chmod(mode_int)   -> 0
+ *    chmod(mode) -> 0
+ *
+ *  Changes the mode of +self+;  returns '0'.
+ *  See {Filesystem Modes}[rdoc-ref:file/filesystem_modes.md]
+ *  and especially {Setting a Mode}[rdoc-ref:file/filesystem_modes.md@Setting+a+Mode].
  *
- *  Changes permission bits on <i>file</i> to the bit pattern
- *  represented by <i>mode_int</i>. Actual effects are platform
- *  dependent; on Unix systems, see <code>chmod(2)</code> for details.
- *  Follows symbolic links. Also see File#lchmod.
+ *  These examples use
+ *  a {helper method}[rdoc-ref:file/filesystem_modes.md@Helper+Method], +mode+,
+ *  that displays a mode both in octal digits and in characters:
+ *
+ *    filepath = 'doc/t.tmp'
+ *    File.write(filepath, 'foo')
+ *    file = File.new(filepath)
+ *    mode(filepath)      # => "100664 -rw-rw-r--"
+ *    file.chmod(0775)
+ *    mode(filepath)      # => "100775 -rwxrwxr-x"
+ *    file.close
+ *    File.delete(filepath)
  *
- *     f = File.new("out", "w");
- *     f.chmod(0644)   #=> 0
  */
 
 static VALUE
diff --git a/iseq.c b/iseq.c
index 4cffe90f4d56a9..d88ade75866c0e 100644
--- a/iseq.c
+++ b/iseq.c
@@ -415,7 +415,6 @@ rb_iseq_mark_and_move(rb_iseq_t *iseq, bool reference_updating)
         struct rb_iseq_variable *v = ISEQ_VARIABLE(iseq);
         if (v) rb_gc_mark_and_move(&v->script_lines);
         rb_gc_mark_and_move(&body->location.label);
-        rb_gc_mark_and_move(&body->location.base_label);
         rb_gc_mark_and_move(&body->location.pathobj);
         if (body->local_iseq) rb_gc_mark_and_move_ptr(&body->local_iseq);
         if (body->parent_iseq) rb_gc_mark_and_move_ptr(&body->parent_iseq);
@@ -711,7 +710,6 @@ iseq_location_setup(rb_iseq_t *iseq, VALUE name, VALUE path, VALUE realpath, int
 
     rb_iseq_pathobj_set(iseq, path, realpath);
     RB_OBJ_WRITE(iseq, &loc->label, name);
-    RB_OBJ_WRITE(iseq, &loc->base_label, name);
     loc->first_lineno = first_lineno;
 
     if (ISEQ_BODY(iseq)->local_iseq == iseq && rb_streql_lit(name, "initialize")) {
@@ -803,9 +801,6 @@ prepare_iseq_build(rb_iseq_t *iseq,
 
     name = rb_fstring(name);
     iseq_location_setup(iseq, name, path, realpath, first_lineno, code_location, node_id);
-    if (iseq != body->local_iseq) {
-        RB_OBJ_WRITE(iseq, &body->location.base_label, ISEQ_BODY(body->local_iseq)->location.label);
-    }
     ISEQ_ORIGINAL_ISEQ_CLEAR(iseq);
     if (body->variable) {
         body->variable->flip_count = 0;
@@ -1619,7 +1614,15 @@ rb_iseq_label(const rb_iseq_t *iseq)
 VALUE
 rb_iseq_base_label(const rb_iseq_t *iseq)
 {
-    return ISEQ_BODY(iseq)->location.base_label;
+    const struct rb_iseq_constant_body *body = ISEQ_BODY(iseq);
+    const rb_iseq_t *local_iseq = body->local_iseq;
+
+    if (local_iseq == NULL || local_iseq == iseq) {
+        return body->location.label;
+    }
+    else {
+        return ISEQ_BODY(rb_iseq_check(local_iseq))->location.label;
+    }
 }
 
 VALUE
@@ -1634,7 +1637,7 @@ rb_iseq_method_name(const rb_iseq_t *iseq)
     struct rb_iseq_constant_body *const body = ISEQ_BODY(ISEQ_BODY(iseq)->local_iseq);
 
     if (body->type == ISEQ_TYPE_METHOD) {
-        return body->location.base_label;
+        return body->location.label;
     }
     else {
         return Qnil;
diff --git a/pathname_builtin.rb b/pathname_builtin.rb
index 6b8108ce0871cc..e538408ff62bc6 100644
--- a/pathname_builtin.rb
+++ b/pathname_builtin.rb
@@ -1503,31 +1503,28 @@ def mtime() File.mtime(@path) end
   # call-seq:
   #   chmod(mode) -> 1
   #
-  # Changes the mode (i.e., permissions) of the entry represented by `self`;
-  # see {File Permissions}[rdoc-ref:File@File+Permissions]:
-  #
-  # ```ruby
-  # # Pathname for a (non-existent) directory.
-  # dir_pn = Pathname('doc/foo') # => #<Pathname:doc/foo>
-  # # Create the directory and fetch its mode.
-  # dir_pn.mkdir
-  # dir_pn.stat.mode.to_s(8) # => "40775"
-  # # Change the directory mode and fetch the new mode.
-  # dir_pn.chmod(0777)
-  # dir_pn.stat.mode.to_s(8) # => "40777"
-  #
-  # # Pathname for a (non-existent) file in the directory.
-  # file_pn = dir_pn.join('t.tmp') # => #<Pathname:doc/foo/t.tmp>
-  # # Create the file and fetch its mode.
-  # file_pn.write('foo')
-  # file_pn.stat.mode.to_s(8) # => "100664"
-  # # Change the file mode and fetch its new mode.
-  # file_pn.chmod(0777)
-  # file_pn.stat.mode.to_s(8) # => "100777"
-  #
-  # # Clean up.
-  # file_pn.delete
-  # dir_pn.rmdir
+  #  Changes the mode of the entry at the path in `self`;  returns `1`.
+  #  See {Filesystem Modes}[rdoc-ref:file/filesystem_modes.md]
+  #  and especially {Setting a Mode}[rdoc-ref:file/filesystem_modes.md@Setting+a+Mode].
+  #
+  #  These examples use
+  #  a {helper method}[rdoc-ref:file/filesystem_modes.md@Helper+Method], `mode`,
+  #  that displays a mode both in octal digits and in characters:
+  #
+  # ```ruby
+  # dirpath = 'doc/foo'
+  # dir_pn = Pathname(dirpath)
+  # dir_pn.mkdir         # Create directory.
+  # mode(dirpath)        # => "040775 drwxrwxr-x"
+  # filepath = File.join(dirpath, 't.tmp')
+  # file_pn = Pathname(filepath)
+  # file_pn.write('bar') # Create file.
+  # mode(filepath)       # => "100664 -rw-rw-r--"
+  # file_pn.chmod(0755)  # Change file mode.
+  # mode(filepath)       # => "100755 -rwxr-xr-x"
+  # dir_pn.chmod(0644)   # Change directory mode.
+  # mode(dirpath)        # => "040644 drw-r--r--"
+  # dir_pn.rmtree        # Clean up.
   # ```
   #
   def chmod(mode) File.chmod(mode, @path) end
diff --git a/vm_backtrace.c b/vm_backtrace.c
index f13d4273179785..19bcd7dc72a0cc 100644
--- a/vm_backtrace.c
+++ b/vm_backtrace.c
@@ -374,7 +374,7 @@ location_base_label(rb_backtrace_location_t *loc)
         return rb_id2str(loc->cme->def->original_id);
     }
 
-    return ISEQ_BODY(loc->iseq)->location.base_label;
+    return rb_iseq_base_label(loc->iseq);
 }
 
 /*
diff --git a/vm_core.h b/vm_core.h
index 2c416859573d63..fc64d278c65b50 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -338,7 +338,6 @@ struct rb_execution_context_struct;
 
 typedef struct rb_iseq_location_struct {
     VALUE pathobj;      /* String (path) or Array [path, realpath]. Frozen. */
-    VALUE base_label;   /* String */
     VALUE label;        /* String */
     int first_lineno;
     int node_id;
diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index bc8b327e35b002..3a0b7324046e59 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -3160,7 +3160,7 @@ warn_unused_block(const rb_callable_method_entry_t *cme, const rb_iseq_t *iseq,
     }
     else if (RTEST(ruby_verbose) || strict_unused_block) {
         VALUE m_loc = rb_method_entry_location((const rb_method_entry_t *)cme);
-        VALUE name = rb_gen_method_name(cme->defined_class, ISEQ_BODY(iseq)->location.base_label);
+        VALUE name = rb_gen_method_name(cme->defined_class, rb_iseq_base_label(iseq));
 
         if (!NIL_P(m_loc)) {
             rb_warn("the block passed to '%"PRIsVALUE"' defined at %"PRIsVALUE":%"PRIsVALUE" may be ignored",
diff --git a/zjit/src/cruby_bindings.inc.rs b/zjit/src/cruby_bindings.inc.rs
index 9e2946ea4030e6..0821ed934d5ac1 100644
--- a/zjit/src/cruby_bindings.inc.rs
+++ b/zjit/src/cruby_bindings.inc.rs
@@ -619,7 +619,6 @@ pub struct iseq_inline_storage_entry {
 #[repr(C)]
 pub struct rb_iseq_location_struct {
     pub pathobj: VALUE,
-    pub base_label: VALUE,
     pub label: VALUE,
     pub first_lineno: ::std::os::raw::c_int,
     pub node_id: ::std::os::raw::c_int,
@@ -2099,7 +2098,7 @@ pub struct zjit_jit_frame {
     pub stack: __IncompleteArrayField<VALUE>,
 }
 pub const ISEQ_BODY_OFFSET_PARAM: zjit_struct_offsets = 16;
-pub const ISEQ_BODY_OFFSET_OUTER_VARIABLES: zjit_struct_offsets = 248;
+pub const ISEQ_BODY_OFFSET_OUTER_VARIABLES: zjit_struct_offsets = 240;
 pub const RUBY_OFFSET_THREAD_RACTOR: zjit_struct_offsets = 24;
 pub type zjit_struct_offsets = u32;
 #[repr(C)]