diff --git a/INSTALL.REPO b/INSTALL.REPO
index 6a6c7a2187b..0a687ce8d9e 100644
--- a/INSTALL.REPO
+++ b/INSTALL.REPO
@@ -15,6 +15,11 @@ example:
 
   $ make configure="--prefix=/opt/emacs CFLAGS='-O0 -g3'"
 
+(We recommend the above CFLAGS if you want to build Emacs that will
+be easy to debug.  In addition, including --enable-checking=all in
+the value of 'configure' above will turn on many run-time checks
+that will identify problematic code sooner rather than later.)
+
 If the above doesn't work, or if you have special build requirements,
 the following information may be helpful.
 
@@ -25,8 +30,9 @@ autoconf  - at least the version specified near the start of
   configure.ac (in the AC_PREREQ command).
 git - at least Git 1.7.1.  If your repository was created by an older
   Git version, you may need to reclone it.
-makeinfo  - not strictly necessary, but highly recommended, so that
-  you can build the manuals.  GNU Texinfo 4.13 or later should work.
+makeinfo  - required to build the manuals (whose Info files are not
+  in the repository).  Installing GNU Texinfo 4.13 or later should
+  work.
 
 To use the autotools, run the following shell command to generate the
 'configure' script and some related files, and to set up your git
@@ -96,6 +102,9 @@ problem is known about and is just waiting for someone to fix it.
 This is especially true for Lisp compilation errors, which are almost
 never platform-specific.
 
+If you need to debug Emacs, the instructions in 'etc/DEBUG' will help.
+You can display that file in Emacs with 'C-h C-d', or just read it with
+any program that can display text files, such as Less.
 
 
 Copyright (C) 2002-2025 Free Software Foundation, Inc.
diff --git a/admin/authors.el b/admin/authors.el
index 8c2acaa546f..57cb8e21c13 100644
--- a/admin/authors.el
+++ b/admin/authors.el
@@ -179,6 +179,7 @@ files.")
     ("Lars Magne Ingebrigtsen" "Lars Ingebrigtsen")
     ("Laurence Warne" "lWarne" "laurencewarne@gmail\\.com")
     (nil "lensplaysgames@gmail\\.com")
+    ("Vladimir Nikishkin" "lockywolf")
     (nil "lorniu@gmail\\.com")
     (nil "LynX@bk\\.ru")
     (nil "lu4nx")
diff --git a/test/lisp/autorevert-tests.el b/test/lisp/autorevert-tests.el
index 319f3285d2d..d8115b444de 100644
--- a/test/lisp/autorevert-tests.el
+++ b/test/lisp/autorevert-tests.el
@@ -581,6 +581,8 @@ This expects `auto-revert--messages' to be bound by
 ;; This is inspired by Bug#44638, Bug#71424.
 (ert-deftest auto-revert-test07-auto-revert-several-buffers ()
   "Check autorevert for several buffers visiting the same file."
+  (skip-unless (or file-notify--library
+                   (file-remote-p temporary-file-directory)))
   ;; (with-auto-revert-test
   (ert-with-temp-file tmpfile
     (let ((auto-revert-use-notify t)
diff --git a/test/lisp/image-tests.el b/test/lisp/image-tests.el
index 69557c83657..455118cb98c 100644
--- a/test/lisp/image-tests.el
+++ b/test/lisp/image-tests.el
@@ -80,14 +80,20 @@
   (should (eq (image-supported-file-p "foo.pbm") 'pbm)))
 
 (ert-deftest image-supported-file-p/optional ()
-  (if (image-type-available-p 'jpeg)
-      (should (eq (image-supported-file-p "foo.jpg") 'jpeg))
-    (should-not (image-supported-file-p "foo.jpg"))))
+  (cond ((image-type-available-p 'jpeg)
+         (should (eq (image-supported-file-p "foo.jpg") 'jpeg)))
+        ((fboundp 'imagemagick-types)
+         (should (eq (image-supported-file-p "foo.jpg") 'imagemagick)))
+        (nil
+         (should-not (image-supported-file-p "foo.jpg")))))
 
 (ert-deftest image-supported-file-p/unsupported-returns-nil ()
   (should-not (image-supported-file-p "foo.some-unsupported-format")))
 
 (ert-deftest image-type-from-file-name ()
+  (skip-unless (and (image-type-available-p 'jpeg)
+                    (image-type-available-p 'png)
+                    (image-type-available-p 'webp)))
   (with-suppressed-warnings ((obsolete image-type-from-file-name))
     (should (eq (image-type-from-file-name "foo.jpg") 'jpeg))
     (should (eq (image-type-from-file-name "foo.png") 'png))
diff --git a/test/lisp/net/shr-tests.el b/test/lisp/net/shr-tests.el
index 4c2fdf0cc70..363cd144e8f 100644
--- a/test/lisp/net/shr-tests.el
+++ b/test/lisp/net/shr-tests.el
@@ -135,8 +135,9 @@ settings, then once more for each (OPTION . VALUE) pair.")
 
 (ert-deftest shr-test/zoom-image ()
   "Test that `shr-zoom-image' properly replaces the original image."
-  (skip-unless (bound-and-true-p image-types))
-  (skip-unless (libxml-available-p))
+  (skip-unless (and (bound-and-true-p image-types)
+                    (image-type-available-p 'png)
+                    (fboundp 'libxml-parse-html-region)))
   (let* ((image (expand-file-name "data/image/blank-100x200.png"
                                   (getenv "EMACS_TEST_DIRECTORY")))
          (image-url (concat "file://" (if (string-prefix-p "/" image)