diff --git a/build/make/Makefile.in b/build/make/Makefile.in
index 49c0cc4ebcf..7a13e5a9e23 100644
--- a/build/make/Makefile.in
+++ b/build/make/Makefile.in
@@ -17,6 +17,7 @@
 # Always use bash for make rules
 SHELL = @SHELL@
 
+ifndef DEBUG_RULES
 # Check a variable that is only set in build/make/install, but not in sage-env, for example
 ifndef SAGE_PKGCONFIG
 # Set by build/bin/sage-sdist, which invokes the Makefile directly in
@@ -25,6 +26,7 @@ ifndef SAGE_SPKG_COPY_UPSTREAM
 $(error This Makefile needs to be invoked by build/make/install)
 endif
 endif
+endif
 
 # Directory to keep track of which packages are installed - relative to installation prefix
 SPKG_INST_RELDIR = var/lib/sage/installed
diff --git a/build/pkgs/bliss/spkg-install.in b/build/pkgs/bliss/spkg-install.in
index 4124a2338e5..b988d6262ce 100644
--- a/build/pkgs/bliss/spkg-install.in
+++ b/build/pkgs/bliss/spkg-install.in
@@ -1,3 +1,7 @@
+if [ "$UNAME" = "Darwin" ]; then
+    LDFLAGS="${LDFLAGS} -Wl,-rpath,${SAGE_LOCAL}/lib"
+    export LDFLAGS
+fi
 cd src
 sdh_cmake -DUSE_GMP=OFF -DCMAKE_VERBOSE_MAKEFILE=ON
 sdh_make
diff --git a/build/pkgs/primecount/spkg-install.in b/build/pkgs/primecount/spkg-install.in
index 0a63840d8cb..7589fad8cb9 100644
--- a/build/pkgs/primecount/spkg-install.in
+++ b/build/pkgs/primecount/spkg-install.in
@@ -1,3 +1,7 @@
+if [ "$UNAME" = "Darwin" ]; then
+    LDFLAGS="${LDFLAGS} -Wl,-rpath,${SAGE_LOCAL}/lib"
+    export LDFLAGS
+fi
 cd src
 
 # Issue #33054: primecount needs "-std=gnu++..."
diff --git a/build/pkgs/primecountpy/spkg-install.in b/build/pkgs/primecountpy/spkg-install.in
index 37ac1a53437..829ebe2fcc5 100644
--- a/build/pkgs/primecountpy/spkg-install.in
+++ b/build/pkgs/primecountpy/spkg-install.in
@@ -1,2 +1,7 @@
+if [ "$UNAME" = "Darwin" ]; then
+    LDFLAGS="${LDFLAGS} -Wl,-rpath,${SAGE_LOCAL}/lib"
+    export LDFLAGS
+fi
+
 cd src
 sdh_pip_install .
diff --git a/build/pkgs/symengine_py/spkg-install.in b/build/pkgs/symengine_py/spkg-install.in
index 37ac1a53437..829ebe2fcc5 100644
--- a/build/pkgs/symengine_py/spkg-install.in
+++ b/build/pkgs/symengine_py/spkg-install.in
@@ -1,2 +1,7 @@
+if [ "$UNAME" = "Darwin" ]; then
+    LDFLAGS="${LDFLAGS} -Wl,-rpath,${SAGE_LOCAL}/lib"
+    export LDFLAGS
+fi
+
 cd src
 sdh_pip_install .
diff --git a/src/bin/sage-env b/src/bin/sage-env
index 61901897bcd..b9221fe3567 100644
--- a/src/bin/sage-env
+++ b/src/bin/sage-env
@@ -370,22 +370,38 @@ if [ -n "$PYTHONHOME" ]; then
 fi
 
 if [ -n "$SAGE_LOCAL" ]; then
-    # On OS X, test whether "ld-classic" is present in the installed
-    # version of the command-line tools. If so, we add "-ld_classic"
-    # to LD_FLAGS. See #36599.
-    # When the full XCode is installed and in use, for example after
-    # "sudo xcode-select -s /Applications/Xcode.app", then "xcode-select -p"
-    # gives "/Applications/Xcode.app/Contents/Developer", but "ld-classic"
-    # is not in the subdirectory "usr/bin/" but rather in the subdirectory
-    # "Toolchains/XcodeDefault.xctoolchain/usr/bin/". See #37237.
-    # However, if LD is set explicitly, as it is within conda on macOS,
-    # do not not do this.
-    if [ "$UNAME" = "Darwin" ] && [ -z "$LD" ] && [ -x "$(xcode-select -p)/usr/bin/ld-classic" -o -x "$(xcode-select -p)/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld-classic" ] ; then
-        LDFLAGS="-L$SAGE_LOCAL/lib -Wl,-ld_classic,-rpath,$SAGE_LOCAL/lib $LDFLAGS"
-    else
-        LDFLAGS="-L$SAGE_LOCAL/lib -Wl,-rpath,$SAGE_LOCAL/lib $LDFLAGS"
+    # Construct and export LDFLAGS
+    if [ "$UNAME" = "Darwin" ]; then
+       LDFLAGS="-L$SAGE_LOCAL/lib $LDFLAGS"
+       # On OS X, use the old linker if it is available.
+       # if "ld-classic" is present in the selected XCode
+       # toolchain, add "-Wl,-ld_classic" to LDFLAGS (see #36599) unless
+       # LD is already set, as it will be with conda on macOS.  When the
+       # selected toolchain is in the Xcode app the output of "xcode-select -p"
+       # is "/Applications/Xcode.app/Contents/Developer", but "ld-classic" is
+       # not in the subdirectory "usr/bin/" but rather in the subdirectory
+       # "Toolchains/XcodeDefault.xctoolchain/usr/bin/".  (See #37237.)
+       if [ -z "$LD" ]; then
+	   # Running xcode-select on a system with no toolchain writes an
+	   # error message to stderr, so redirect stderr to /dev/null. 
+	   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"
+               fi
+           else
+               # On a macOS system with no toolchain we don't want this script
+               # to call gcc because that will also print an error message to
+               # stderr.  We can avoid this by setting AS and LD to their
+               # default values.
+               AS=as
+               LD=ld
+	   fi
+       fi
     fi
     if [ "$UNAME" = "Linux" ]; then
+	LDFLAGS="-L$SAGE_LOCAL/lib -Wl,-rpath,$SAGE_LOCAL/lib $LDFLAGS"
         LDFLAGS="-Wl,-rpath-link,$SAGE_LOCAL/lib $LDFLAGS"
     fi
     export LDFLAGS