--- Makefile.orig	2021-01-18 12:13:12 UTC
+++ Makefile
@@ -1,7 +1,7 @@
 TARGET := klystrack
 KLYSTRON=klystron
 ECHO := echo
-CFG := debug
+CFG ?= debug
 EXE := bin.$(CFG)/$(TARGET)
 MACHINE :=
 NSIS := C:/program\ files\ \(x86\)/nsis/makensis.exe -V2 -NOCD
@@ -10,7 +10,7 @@ MAKEBUNDLE := $(KLYSTRON)/tools/bin/makebundle.exe
 UPLOAD := cmd.exe /c upload.bat
 DLLS := zip/data/SDL2_image.dll zip/data/SDL2.dll
 EXT := .c
-CC := gcc
+CC ?= gcc
 CDEP := $(CC) -E -MM
 ARCHIVE := klystrack
 INSTALLER := klystrack.exe
@@ -21,7 +21,7 @@ REV := cp -f
 
 PREFIX ?= /usr
 BINDIR = $(PREFIX)/bin
-CFLAGS := $(MACHINE) -ftree-vectorize -std=gnu99 -Wno-strict-aliasing
+CFLAGS ?= $(MACHINE) -ftree-vectorize -std=gnu99 -Wno-strict-aliasing
 
 ifdef COMSPEC
 	# Compiling for Windows
@@ -72,7 +72,7 @@ else
   CFLAGS += -O3 -pg -Wall
  else
   ifeq ($(CFG),release)
-   CFLAGS += -O3 -Wall -s
+   CFLAGS += -Wall
    ifdef COMSPEC
 	 CFLAGS += -mwindows
    endif
@@ -136,8 +136,8 @@ endef
 
 build: Makefile src/version.h src/version_number.h
 	$(Q)touch src/version
-	$(Q)$(MAKE) -C $(KLYSTRON) CFG=$(CFG) EXTFLAGS="$(EXTFLAGS)"
-	$(Q)$(MAKE) all CFG=$(CFG) EXTFLAGS="$(EXTFLAGS)"
+	$(Q)$(MAKE_ENV)$(MAKE) -C $(KLYSTRON) CFG=$(CFG) EXTFLAGS="$(EXTFLAGS)"
+	$(Q)$(MAKE_ENV)$(MAKE) all CFG=$(CFG) EXTFLAGS="$(EXTFLAGS)"
 
 src/version.h: src/version
 	$(Q)echo '#ifndef VERSION_H' > ./src/version.h