OS X: do not use -ld_classic

src/bin/sage-env

@@ -383,12 +383,15 @@ if [ -n "$SAGE_LOCAL" ]; then
        # "Toolchains/XcodeDefault.xctoolchain/usr/bin/".  (See #37237.)
        if [ -z "$LD" ]; then
 	   # Running xcode-select on a system with no toolchain writes an
-	   # error message to stderr, so redirect stderr to /dev/null. 
+	   # error message to stderr, so redirect stderr to /dev/null.
 	   XCODE_PATH=$(/usr/bin/xcode-select -p 2> /dev/null)
 	   if [ -n $XCODE_PATH ]; then
                if [ -x "$XCODE_PATH/usr/bin/ld-classic" -o \
 		       -x "$XCODE_PATH/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld-classic" ]; then
-		   LDFLAGS="$LDFLAGS -Wl,-ld_classic"
+                   # Add -ld_classic only if -ld_classic is not deprecated.
+                   if [ -z "$(ld -ld_classic 2>&1 | grep 'ld_classic is deprecated')" ]; then
+		       LDFLAGS="$LDFLAGS -Wl,-ld_classic"
+                   fi
                fi
            else
                # On a macOS system with no toolchain we don't want this script

src/sage/doctest/parsing.py

@@ -1516,6 +1516,21 @@
             pythran_numpy_warning_regex = re.compile(r'WARNING: Overriding pythran description with argspec information for: numpy\.random\.[a-z_]+')
             got = pythran_numpy_warning_regex.sub('', got)
             did_fixup = True
+
+        if "ld_classic is deprecated" in got:
+            # New warnings as of Oct '24, Xcode 16.
+            ld_warn_regex = re.compile("ld: warning: -ld_classic is deprecated and will be removed in a future release")
+            got = ld_warn_regex.sub('', got)
+            did_fixup = True
+
+        if "duplicate libraries" in got:
+            # New warnings as of Sept '23, OS X 13.6, new command-line
+            # tools. In particular, these seem to come from ld in
+            # Xcode 15.
+            dup_lib_regex = re.compile("ld: warning: ignoring duplicate libraries: .*")
+            got = dup_lib_regex.sub('', got)
+            did_fixup = True
+
         return did_fixup, want, got
 
     def output_difference(self, example, got, optionflags):

src/sage/tests/cmdline.py

@@ -776,4 +776,13 @@ def test_executable(args, input='', timeout=100.0, pydebug_ignore_warnings=False
                 p.stderr.close()
             err.append(s)
 
-    return (''.join(out), ''.join(err), p.wait())
+    # In case out or err contains a quoted string, force the use of
+    # double quotes so that the output is enclosed in single
+    # quotes. This avoids some doctest failures with some versions of
+    # OS X and Xcode.
+    out = ''.join(out)
+    out = out.replace("'", '"')
+    err = ''.join(err)
+    err = err.replace("'", '"')
+
+    return (out, err, p.wait())