diff --git a/Makerules b/Makerules
--- a/Makerules
+++ b/Makerules
@@ -81,22 +81,10 @@ HAVE_GLUT ?= yes
 SYS_GLUT_CFLAGS := -Wno-deprecated-declarations
 SYS_GLUT_LIBS := -framework GLUT -framework OpenGL
 
-CC = xcrun cc
-AR = xcrun ar
-LD = xcrun ld
-RANLIB_CMD = xcrun ranlib $@
-
-# Linux uses pkg-config for system libraries.
-else ifeq "$(OS)" "Linux"
-
 HAVE_PTHREAD := yes
 SYS_PTHREAD_CFLAGS :=
 SYS_PTHREAD_LIBS := -lpthread
 
-HAVE_GLUT := yes
-SYS_GLUT_CFLAGS :=
-SYS_GLUT_LIBS := -lglut -lGL
-
 ifeq "$(shell pkg-config --exists 'libcrypto <= 1.0.1t' && echo yes)" "yes"
 HAVE_LIBCRYPTO := yes
 SYS_LIBCRYPTO_CFLAGS := -DHAVE_LIBCRYPTO $(shell pkg-config --cflags libcrypto)
@@ -113,7 +101,7 @@ SYS_CURL_CFLAGS += $(shell pkg-config --cflags openssl)
 SYS_CURL_DEPS += $(shell pkg-config --libs openssl)
 endif
 endif
-SYS_CURL_DEPS += -lpthread -lrt
+SYS_CURL_DEPS += -lpthread
 
 ifeq "$(shell pkg-config --exists x11 xext && echo yes)" "yes"
 HAVE_X11 := yes