Make build env script more robust, take it out of makefile

makefile

@@ -1,8 +1,8 @@
-install:
-#	Install opam and dependencies	
-	scripts/install_build_environment.sh
+# Use install-deps instead of 'install' because usually 'make install' adds a
+# binary to the system path and we don't want to confuse users
+install-deps:
 #	Install ligo/tezos specific system-level dependencies
-	scripts/install_native_dependencies.sh
+	sudo scripts/install_native_dependencies.sh
 
 build-deps:
 #	Create opam dev switch locally for use with Ligo, add merlin/etc

scripts/install_build_environment.sh

@@ -1,3 +1,20 @@
+# This script installs opam for the user. It should NOT be included in any makefiles/etc.
+
+if [ -n "`which opam`"]
+then
+    if [ -n "`opam --version | grep -P "2\..\.."`" ]
+    then
+	echo "Opam 2.x seems to already exist, exiting..."
+	exit 1
+    fi
+else
+    read -p "This script will upgrade opam to the 2.x series, are you okay with that? (y/n)" choice1
+    case "$choice1" in
+	y|Y ) : ;;
+	n|N ) exit ;;
+    esac
+fi
+
 sudo apt-get install -y make \
      m4 \
      gcc \
@@ -10,19 +27,35 @@ if [ -n "`uname -a | grep -i ubuntu`" ]
 then
     sudo add-apt-repository -y ppa:avsm/ppa
     sudo apt-get update
-    sudo apt-get install -y opam
+    sudo apt-get install opam
 else
     # I'm going to assume here that we're on x86_64, 32-bit users should be basically
     # extinct at this point right?
     curl -L https://github.com/ocaml/opam/releases/download/2.0.4/opam-2.0.4-x86_64-linux \
-	 --output opam
+	 --output opam_temp_version_2_0_4.bin
     if [ "`openssl sha256 -r opam`" = "373e34f92f282273d482537f8103caad0d17b6f2699ff504bed77f474cb0c951 *opam" ]
     then
-	   sudo mv opam /usr/local/bin/opam
-	   sudo chmod +x /usr/local/bin/opam
+	# Stay paranoid, in case other checks fail don't want to overrwrite
+	# user's opam on accident
+	chmod +x opam_temp_version_2_0_4.bin # Set execute so we can get version
+	if [ -e /usr/local/bin/opam ]
+	then
+	    opam_old_v=`/usr/local/bin/opam --version`
+	    opam_new_v=`opam_temp_version_2_0_4.bin --version`
+	    read -p "This will overrwrite the opam you have in /usr/local/bin (version $opam_old_v) with version $opam_new_v, do you actually want to do that? Type yes. (yes/n)" choice2
+	else
+	    choice2="yes"
+	fi
+	if [ $choice2 = "yes" ]
+	then
+	    sudo mv opam_temp_version_2_0_4.bin /usr/local/bin/opam
+	else
+	    rm opam_temp_version_2_0_4.bin
+	    exit
     else
 	echo "opam file hash doesn't match what was recorded at time of signature verification!"
 	echo "(If you actually get this message, you should probably file an issue)"
+	echo "https://gitlab.com/ligolang/ligo/issues"
 	exit 1
     fi	   	   
 fi