this is a bourne script, bash is not needed

Don't use /bin/bash ! Many systems do not have bash there (they
might have it at /usr/local/bin/bash, for example). Don't specify
bash unless you specifically need bash features -- many systems
do not have bash installed by default.

Makefile

@@ -1,4 +1,4 @@
-localversion = $(shell bash scripts/localversion.sh)
+localversion = $(shell sh scripts/localversion.sh)
 
 cflags = -Wall -Iinclude -Iinclude/asm/gameboy -DLOCALVERSION=\"$(localversion)\" -g -std=c99 -D_POSIX_C_SOURCE=200112L
 

scripts/localversion.sh

@@ -1,4 +1,4 @@
-#! /bin/bash
+#!/bin/sh
 
 #
 # Use git to figure out which version we are using.