use usr/bin/env bash since it's more general then /bin/bash

bin/common

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Finds in dotty build file a line containing PATTERN
 # returns last "" escaped string in this line

bin/dotc

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # This script is used for running compiler standalone(outside of sbt)
 # it's based on miniboxing script and paulp's launcher script
 

bin/dotr

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Try to autodetect real location of the script
 DOTTY_ROOT="$(readlink "$0")"              #  relative, symbolic links resolved