rustup diff

rustup.sh.diff

diff --git a/rustup.sh b/rustup.sh
index 62a2b35..9350e55 100755
--- a/rustup.sh
+++ b/rustup.sh
@@ -231,6 +231,42 @@ validate_opt () {
 
 probe_need CFG_CURL  curl
 
+version() {
+  local bin_dir=$1
+  local bin=$2
+  local arg=
+  if [ "$bin" = "cargo" ]
+  then
+    arg="version"
+  else
+    arg="--version"
+  fi
+  echo $($bin_dir/$bin $arg 2>&1)
+}
+
+version_revision() {
+  local vers=$1
+  echo $(echo "$vers" |sed -E "s/[^(]+\(([^ ]+).*/\1/")
+}
+
+print_version_diff() {
+  local prev=$1
+  local cur=$2
+  local upstream=$3
+  if [ "$prev" = "$cur" ]
+  then
+    echo "    Version was the same"
+  else
+    echo "    Went from version:"
+    echo "    $prev"
+    echo "    to"
+    echo "    $cur"
+    local v1=$(version_revision "$prev")
+    local v2=$(version_revision "$cur")
+    echo "    See diff here: ${upstream}/compare/${v1}...${v2}"
+  fi
+}
+
 CFG_SRC_DIR="$(cd $(dirname $0) && pwd)/"
 CFG_SELF="$0"
 CFG_ARGS="$@"
@@ -443,9 +479,16 @@ then
 fi
 
 MAYBE_PREFIX=
+BIN_DIR="/usr/local/bin"
 if [ -n "${CFG_PREFIX}" ]
 then
 	MAYBE_PREFIX="--prefix=${CFG_PREFIX}"
+	BIN_DIR="${CFG_PREFIX}/bin"
+fi
+
+PREV_VERS=$(version "$BIN_DIR" rustc)
+if [ -z "${CFG_DISABLE_CARGO}" ]; then
+  PREV_CARGO_VERS=$(version "$BIN_DIR" cargo)
 fi
 
 sh "${LOCAL_INSTALL_SCRIPT}" "${MAYBE_UNINSTALL}" "${MAYBE_PREFIX}"
@@ -453,6 +496,10 @@ if [ $? -ne 0 ]
 then
 	rm -Rf "${TMP_DIR}"
 	err "failed to install Rust"
+elif [ -n "${PREV_VERS}" ]
+then
+  VERS=$(version "$BIN_DIR" rustc)
+  print_version_diff "$PREV_VERS" "$VERS" "https://github.com/rust-lang/rust"
 fi
 
 if [ -z "${CFG_DISABLE_CARGO}" ]; then
@@ -468,6 +515,12 @@ if [ -z "${CFG_DISABLE_CARGO}" ]; then
     then
             rm -Rf "${TMP_DIR}"
             err "failed to install Cargo"
+    elif [ -n "${PREV_CARGO_VERS}" ]
+    then
+      CARGO_VERS=$(version "$BIN_DIR" cargo)
+      print_version_diff "$PREV_CARGO_VERS" \
+                         "$CARGO_VERS" \
+                         "https://github.com/rust-lang/cargo"
     fi
 fi
 

Don't know where the source to rustup.sh lives but wanted to share this useful patch.

It will print a message saying what version you changed from and to and gives a github link to the comparison between the previous and current version.

e.g.

Rust is ready to roll.

Went from version:
rustc 0.12.0-nightly (dc987adfc 2014-10-04 23:42:07 +0000)
to
rustc 0.12.0-nightly (b5ba2f551 2014-10-06 20:27:14 +0000)
See diff here: https://github.com/rust-lang/rust/compare/dc987adfc...b5ba2f551

rust-lang/rust@dc987ad...b5ba2f5