--- /dev/null
+--- a/mgr/requirements 2014-01-06 22:40:25.000000000 +0800
++++ b/mgr/requirements 2019-12-09 22:33:53.375723322 +0800
+@@ -157,7 +157,7 @@
+ macro cdebugflags "" \
+ debug "$(debug_option)"
+
+-macro cflags "" \
++macro cflags "${CFLAGS}" \
+ LynxOS-VGPW2 "-X" \
+ insure "-std1" \
+ HP-UX "+Z" \
+@@ -252,7 +252,7 @@
+ hp700_ux101 "-fpic" \
+ HP-UX "+Z -Wc,-ansi_for_scope,on" \
+ hp_ux102 "-z +p -Wc,-ansi_for_scope,on +O2 +Onoinitcheck" \
+- Linux "-pipe -ansi -pedantic -W -Wall -Wwrite-strings -Wpointer-arith -Woverloaded-virtual " \
++ Linux "${CXXFLAGS}" \
+ SunOS "-KPIC" \
+ VisualC '/nologo /DWIN32 /MD /W3 $(includes) /c /EHsc'
+
+@@ -403,7 +403,7 @@
+ macro shlibflags "" \
+ HP-UX "-Wl,-a,shared -b +Z -q -Wl,+s -Wl,+vallcompatwarnings" \
+ OSF1 "-shared -expect_unresolved '*'" \
+- Linux "-shared" \
++ Linux "-shared ${LDFLAGS}" \
+ CYGWIN "-shared" \
+ SunOS "$(debug_option)" \
+ VisualC "" \